Chosen Ciphertext Secure Identity-Based Broadcast Encryption in the Standard Model

To give concurrent consideration both the efficiency and the security(intensity of intractable problem) in the standard model,a chosen ciphertext secure identity-based broadcast encryption is proposed.Against the chosen ciphertext security model,by using identity(ID) sequence and adding additional information in ciphertext,the self-adaptive chosen identity security(the full security) and the chosen ciphertext security are gained simultaneously.The reduction of scheme's security is the decisional bilinear Diffie-Hellman(BDH) intractable assumption,and the proof of security shows that the proposed scheme is indistinguishable against adaptive chosen ciphertext attacks in the standard model under the decisional BDH intractable assumption.So the security level is improved,and it is suitable for higher security environment.

The Explanation for the Origin of the Higgs Scalar and for the Yukawa Couplings by the Spin-Charge-Family Theory

The spin-charge-family theory is a kind of the Kaluza-Klein theories, but with two kinds of the spin connection fields, which are the gauge fields of the two kinds of spins. The SO(13,1) representation of one kind of spins manifests in d = (3 + 1) all the properties of family members as assumed by the standard model;the second kind of spins explains the appearance of families. The gauge fields of the first kind, carrying the space index m = (0,...,3), manifest in d = (3 + 1) all the vector gauge fields assumed by the standard model. The gauge fields of both kinds of spins, which carry the space index (7, 8) gaining at the electroweak break nonzero vacuum expectation values, manifest in d = (3 + 1) as scalar fields with the properties of the Higgs scalar of the standard model with respect to the weak and the hyper charge ( and , respectively), while they carry additional quantum numbers in adjoint representations, offering correspondingly the explanation for the scalar Higgs and the Yukawa couplings, predicting the fourth family and the existence of several scalar fields. The paper 1) explains why in this theory the gauge fields are with the scalar index s = (5,6,7,8) doublets with respect to the weak and the hyper charge, while they are with respect to all the other charges in the adjoint representations;2) demonstrates that the spin connection fields manifest as the Kaluza-Klein vector gauge fields, which arise from the vielbeins;and 3) explains the role of the vielbeins and of both kinds of the spin connection fields.

The Spin-Charge-Family Theory Is Explaining the Origin of Families,of the Higgs and the Yukawa Couplings

The (extremely efficient) standard model of the elementary particles and fields makes several assumptions, which call for explanations. Any theory offering next step beyond the standard model must explain at least the existence and properties of families and their members and correspondingly the existence of the scalar Higgs and the Yukawa couplings, which in this model take care of masses of fermions and weak bosons and influence the decaying properties of families. The spin-charge-family theory [1-11] is offering a possible explanation for the assumptions of the standard model—for the appearance of families and their members (for the charges of a family members), for the gauge fields, for the scalar fields—interpreting the standard model as its low energy effective manifestation. The spin-charge-family theory predicts at the low energy regime two decoupled groups of four families of quarks and leptons. The predicted fourth family waits to be observed, while the stable fifth family is the candidate to form the dark matter. In this paper properties of families are analysed. The appearance of several scalar fields, all in the bosonic (adjoint) representations with respect to the family groups, while they are doublets with respect to the weak charge, is presented, their properties discussed, it is explained how these scalar fields can effectively be interpreted as the standard model Higgs and the Yukawa couplings. The spin-charge-family theory predicts that there are no supersymmetric partners of the observed fermions and bosons.

Effects of family non-universal Z′model in angular observables of B→(ρ,a_(1))µ^(+)µ^(−)decays

We present the angular distribution of the four-fold B→ρ(→ππ)µ^(+)µ^(−) and B→a_(1)(→ρ_(Ⅱ).⊥π)µ^(+)µ^(−) decays in the Standard Model and family non-universal Z'model.At the quark level,these decays are govered by the b→dµ^(+)µ^(−) transition.Along with different angular observables,we provide predictions of differential branching ra.tios,forward-backward asymmetry,and longitudinal polarization fractions of ρ and a_(1) mesons.Our analysis showsthat the signatures of the fimily non-universal Z’model are more distinct in the observables associated with the B→ρ(→ππ)µ^(+)µ^(−) decay than in those associated with the B→a_(1)(→ρ_(Ⅱ).⊥π)µ^(+)µ^(−) decay.Future measurements ofthe predicted angular observables,both at current and fiuture high energy colliders,will provide useful complement.ary data required to clarify the structure of the family non-universal Z' model in |△b|=△d|=1 processes.

Model-independent Veltman condition,naturalness and the little hierarchy problem

We adopt a bottom-up Effective Field Theory(EFT)approach to derive a model-independent Veltman condition to cancel out the quadratic divergences in the Higgs mass.We show using the equivalence theorem that all the deviations in the Higgs couplings to the W and Z from the SM predictions should vanish.We argue based on tree-level unitarity that any new physics that naturally cancels out the quadratic divergences should be ≤19 TeV.We show that the level of fine-tuning required is unless the O(0:1%-1%) UV sector has a symmetry that forces the satisfaction of the model-independent Veltman condition,in which case all fine-tuning is eliminated.We also conjecture that,if no new physics that couples to the Higgs is observed up to~19 TeV,or if the Higgs couplings to the SM particles conform to the SM predictions,then the Higgs either does not couple to any UV sector or is fine-tuned.

Associated Production of Z Boson and a Pair of New Quarks at LHC

The associated production of Z boson and a pair of new quarks at the Large Hadron Collider （LHC） is studied. The cross sections for both sequential fermions and vector-like fermions are presented. It is found that for sequential fermions the cross sections can reach 1 - 10^2 /b for heavy quark mass mQ from 1000 GeV to 200 GeV. For vector-like quarks, the cross sections are suppressed by mixing parameter sin OL. Focusing on process pp → b＇b＇, we investigate the possibility of detecting the 6l 4- 2j signal. For a b＇ with light mass and a large branching ratio of b＇ → bZ, it is found that only several signal events （ parton level ） can be produced with 1000 fb^-1 integrated luminosity. Although the signal events are rare, all the final states are produced centrally and multi lepton final states are clear at hadron collider, which could be easily detected.

Branching Ratios from H→γγ and H→Zγ with a 125 GeV Higgs Boson

Motivated by the recent result reported from LHC on the di-photon search from the Standard Model (SM) Higgs boson, we obtain limits on the anomalous couplings Hγγ and HZγ. We also perform a calculation at tree level of the decay widths as well as of the branching ratios for the reactions H → γγ and H → Zγ in the context of effective lagrangian for Higgs boson masses 115 ≤MH ≤ 130 GeV. We find that the decay widths and branching ratios from these reactions enhanced significantly due to the anomalous Hγγ and HZγ vertex, which would lead to measurable effects in Higgs signals at the LHC. Moreover, our results complement other studies on the channels H → γγ and H → Zγ.

New theory of Lorentz violation from a general principle

We report that a general principle of physical independence of mathematical background manifolds brings a replacement of common derivative operators by co-derivative ones. Then we obtain a new Lagrangian for the ordinary minimal standard model with supplementary terms containing the Lorentz invariance violation information measured by a new matrix, denoted as the Lorentz invariance violation matrix. We thus provide a new fundamental theory to study Lorentz invariance violation effects consistently and systematically.

Analysis of Λ_b →Λl^+l^- rare decays in a non-universal Z’ model

We investigate the rare baryonic Λ_b→Λl^＋l^- decays in a non-universal Z＇ model, which is one of the wellmotivated extensions of the standard model（SM）. Considering the effects of Z-mediated flavour-changing neutral currents（FCNCs） we analyse the differential decay rate, forward-backward asymmetries and lepton polarisation asymmetries for the Λb→Λl^＋l^- decays. We find significant deviations from their SM predictions, which could indicate new physics arising from the Z gauge boson.

Linear seesaw model with T7 symmetry for neutrino mass and mixing

We propose a low-scale Standard Model extension with T_(7)×Z_(4)×Z_(3)×Z_(2) symmetry that can successfully explain observed neutrino oscillation results within the 3σrange.Small neutrino masses are obtained via the linear seesaw mechanism.Normal and inverted neutrino mass orderings are considered with three lepton mixing angles in their experimentally allowed 3σranges.The model provides a suitable correlation between the solar and reactor neutrino mixing angles,which is consistent with the TM2 pattern.The prediction for the Dirac phase isδCP∈(295.80,330.0)°for both normal and inverted orderings,including its experimentally maximum value,while those for the two Majorana phases areη1∈(349.60,356.60)°,η2=0 for normal ordering andη1∈(3.44,10.37)°,η2=0 for inverted ordering.In addition,the predictions for the effective neutrino masses are consistent with the pre sent experimental bounds.

What can a heavy U(1)B-L Z'boson do to the muon(g-2)u anomaly and to a new Higgs boson mass?

The minimal U(1)B_L extension of the Standard Model(B-L-SM)offers an explanation for neutrino mass generatio n via a seesaw mechanism;it also offers two new physics states,namely an extra Higgs bos on and a new Z'gauge boson.The emerge nee of a second Higgs particle as well as a new Z'gauge boson,both lin ked to the breaking of a local U(1)B_L symmetry,makes the B-L-SM rather constrained by direct searches in Large Hadron Collider(LHC)experiments.We investigate the phenomenological status of the B-L-SM by confr on ting the new physics predictions with the LHC and electroweak precision data.Taking into account the current bounds from direct LHC searches,we demonstrate that the prediction for the muon(g-2)u anomaly in the B-L-SM yields at most a contribution of approximately 8.9×10^-12,which represents a tension of 3.28 standard deviations,with the current 1σuncertainty,by means of a Z'boson if its mass is in the range of 6.3 to 6.5 TeV,within the reach of future LHC runs.This means that the B-L-SM,with heavy yet allowed Z‘bos on mass range,in practice,does not resolve the tension between the observed anomaly in the muon(g-2)u and the theoretical prediction in the Standard Model.Such a heavy Z'boson also implies that the minimal value for the new Higgs mass is of the order of 400 GeV.

Two-component millicharged dark matter and the EDGES 21 cm signal

We propose a two-component dark matter explanation to the EDGES 21 cm anomalous signal.The heavier dark matter component is long-lived,and its decay is primarily responsible for the relic abundance of the lighter dark matter,which is millicharged.To evade the constraints from CMB,underground dark matter direct detection,and XQC experiments,the lifetime of the heavier dark matter has to be larger than 0.1τU,whereτU is the age of the universe.Our model provides a viable realization of the millicharged dark matter model to explain the EDGES 21 cm signal,since the minimal model in which the relic density is generated via thermal freeze-out has been ruled out by various constraints.

Joint explanation of W-mass and muon g-2 in the 2HDM

Because both W-mass and muon g-2 can be affected by mass splittings among extra Higgs bosons(H,A,H^(±))in a two-Higgs-doublet model,we take a model with μ-τ lepton flavor violation interactions to examine the two anomalies reported by CDFⅡ and FNAL.We obtain the following observations:(ⅰ)Combined with theoretical constraints,the CDF W-mass measurement disfavors H or A degenerating in mass with H^(±)but allows H and A to degenerate.The mass splitting between H^(±)and H/A must be larger than 10 GeV.m_(H) and m_(A) are favored to be smaller than 650 GeV for m_(H)<120 GeV and allowed to have larger values with increasing m_(H).(ⅱ)After imposing other relevant experimental constraints,there are parameter spaces that simultaneously satisfy(at the 2σ level)the CDF W-mass,FNAL muon g-2,and data on lepton universality in τ decays;however,the mass splittings among extra Higgs bosons are strictly constrained.

Neutrino masses,cosmological inflation and dark matter in a variant U(1)B-L model with type II seesaw mechanism

In this study,we implemented the type Ⅱ seesaw mechanism into the framework of the U(l)B-L gauge model.To achieve this,we added a scalar triplet,A,to the canonical particle content of the U(l)B-Lgauge model.By imposing that the U(l)B-L gauge symmetry be spontaneously broken at TeV scale,we show that the type Ⅱ seesaw mechanism is realized at an intermediate energy scale,more precisely,at approximately 109 GeV.To prevent heavy right-handed neutrinos from disturbing the mechanism,we evoke a Z2 discrete symmetry.Interestingly,as a result,we have standard neutrinos with mass around eV scale and right-handed neutrinos with mass in TeV scale,with the lightest one fulfilling the condition of dark matter.We developed all of these in this study.In addition,we show that the neutral component of Δ may perform unproblematic non-minimal inflation with loss of unitarity.

纳赫兹引力波对单态暗物质模型中电弱相变的影响

受脉冲星定时阵列合作组最近观测到的纳赫兹级随机引力波证据的启发,本文在标准模型的单态扩展中探讨了利用极端过冷的电弱相变解释这些观测结果的可能性,并考虑了相变对于暗物质的影响.研究结果表明,通过精细调节模型参数,相应的渗透温度可以连续降低到1 GeV甚至更低.在如此低的渗透温度下,单态暗物质可能在电弱相变之前就脱离热平衡,从而从热辐射中冻结出来.因此,相变期间产生的熵可以显著影响暗物质的残留密度.这减轻了单态扩展模型中同时解释重子生成和满足暗物质直接探测限制的压力,暗示着所考虑的新物理模型可能存在更广阔的参数空间,并可在未来的实验中得到验证.

Gravitational waves from cosmic strings associated with pseudo-Nambu-Goldstone dark matter

We study stochastic gravitational waves from cosmic strings generated in an ultraviolet-complete model for pseudo-Nambu-Goldstone dark matter with a hidden U(1)gauge symmetry.The dark matter candidate in this model can naturally evade direct detection bounds and easily satisfy other phenomenological constraints.The bound on the dark matter lifetime implies an ultraviolet scale higher than 10^(9)GeV.The spontaneous U(1)symmetry breaking at such a high scale would induce cosmic strings with high tension,resulting in a stochastic gravitational wave background with a high energy density.We investigate the constraints from current gravitational wave experiments as well as the future sensitivity.We find that most viable parameter points can be well studied in future gravitational waveexperiments.

Probing new physics in dimension-8 neutral gauge couplings at e^+e^-colliders

Neutral triple gauge couplings(nTGCs)are absent in the standard model effective theory up to dimension-6 operators,but could arise from dimension-8 effective operators.In this work,we study the pure gauge operators of dimension-8 that contribute to nTGCs and are independent of the dimension-8 operator involving the Higgs doublet.We show that the pure gauge operators generate both ZγZ^*and Zγγ^*vertices with rapid energy dependence∝E^5,which can be probed sensitively via the reaction e^+e^-→Zγ.We demonstrate that measuring the nTGCs via the reaction e^+e^-→Zγfollowed by Z→qq decays can probe the new physics scales of dimension-8 pure gauge operators up to the range(1-5)TeV at the CEPC,FCC-ee and ILC colliders with s~(1/2)=(0.25-1)TeV,and up to the range(10-16)TeV at CLIC with s~(1/2)=(3-5)TeV,assuming in each case an integrated luminosity of 5 ab~(-1).We compare these sensitivities with the corresponding probes of the dimension-8 nTGC operators involving Higgs doublets and the dimension-8 fermionic contact operators that contribute to the e^+e^-Zγvertex.

Resonant production of color octet muons at Future Circular Collider-based muon-proton colliders

We investigate the resonant production of color octet muons in order to explore the discovery potential of Future Circular Collider（FCC）-based μp colliders.It is shown that the search potentials of μp colliders essentially surpass the potential of the LHC and would exceed that of the FCC pp collider.

Parity violation in electron scattering

By comparing the cross Sections for left- and right-handed electrons scattered from various unpolarized nuclear targets, the small parity-violating asymmetry can be measured. These asymmetry data probe a wide variety of important topies, including searches for new fundamental interactions and important features of nuclear structure that cannot be studied with other probes. A special feature of these experiments is that the results are interpreted with remarkably few theoretical uncertainties, which justifies pushing the experiments to the highest possible precision. To measure the small asymmetries accurately, a number of novel experimental techniques have been developed.

Gravitational waves from cosmic strings after a first-order phase transition

We study the possibility of probing high scale phase transitions that are inaccessible by LIGO.Our study shows that the stochastic gravitational-wave radiation from cosmic strings that are formed after the first-order phase transition can be detected by space-based interferometers when the phase transition temperature is T_(n)~O(10^(8−11))GeV.