Combined estimation for multi-measurements of branching ratio

A maximum likelihood method is used to deal with the combined estimation of multi-measurements of a branching ratio, where each result can be presented as an upper limit. The joint likelihood function is constructed using observed spectra of all measurements and the combined estimate of the branching ratio is obtained by maximizing the joint likelihood function. The Bayesian credible interval or upper limit of the combined branching ratio,is given in cases both with and without inclusion of systematic error.

Monogamy and polygamy relations of multiqubit entanglement based on unified entropy

Monogamy relation is one of the essential properties of quantum entanglement,which characterizes the distribution of entanglement in a multipartite system.By virtual of the unified-(q,s)entropy,we obtain some novel monogamy and polygamy inequalities in general class of entanglement measures.For the multiqubit system,a class of tighter monogamy relations are established in term of the α-th power of unified-(q,s)entanglement for α≥1.We also obtain a class of tighter polygamy relations in the β-th(0≤β≤1)power of unified-(q,s)entanglement of assistance.Applying these results to specific quantum correlations,e.g.,entanglement of formation,Renyi-q entanglement of assistance,and Tsallis-q entanglement of assistance,we obtain the corresponding monogamy and polygamy relations.Typical examples are presented for illustration.Furthermore,the complementary monogamy and polygamy relations are investigated for the α-th(0≤α≤ 1)and β-th(β≥1)powers of unified entropy,respectively,and the corresponding monogamy and polygamy inequalities are obtained.

The Higgs signatures at the CEPC CDR baseline

As a Higgs factory, the CEPC(Circular Electron-Positron Collider) project aims at precision measurements of the Higgs boson properties. A baseline detector concept, APODIS(A PFA Oriented Detector for the HIggS factory), has been proposed for the CEPC CDR(Conceptual Design Report) study. We explore the Higgs signatures for this baseline design with ■ Higgs events. The detector performance for reconstructing charged particles, photons and jets is quantified with H→μμ, γγ and jet final states, respectively. The resolutions of reconstructed Higgs boson mass are comparable for the different decay modes with jets in the final states. We also analyze the H→WW~* and ZZ* decay modes, where a clear separation between different decay cascades is observed.

Study of the Standard Model and Majorana neutrino contributions to

Lepton number violation processes can be induced by the Majorana neutrino exchange, which provide evidence for the Majorana nature of neutrinos. In addition to the natural explanation of the small neutrino masses,Type-I seesaw mechanism predicts the existence of Majorana neutrinos. The aim of this work is to study the B meson rare decays B^+→K^((*))+μ^+μ^-in the Standard Model and its extensions, and then to investigate the same-sign decay process B^+→K^((*)-)μ^+μ^+. The corresponding dilepton invariant mass distributions are calculated. It is found that the dilepton angular distributions could shed light on the properties of new interactions induced by Majorana neutrinos.

Interference effects on Higgs mass measurement in e^＋e^-→H(γγ)Z at CEPC

A high luminosity Circular Electron Positron Collider(CEPC) as a Higgs Factory will be helpful for precision measurements of the Higgs mass. The signal-background interference effect is carefully studied for the Higgs diphoton decay mode in associated Z boson production at future e^+e^-colliders at energy 246 GeV. The mass shifts go up from about 20 MeV to 50 MeV for the experimental mass resolution ranging from 0.8 GeV to 2 GeV.

Gravitational Waves, baryon asymmetry of the universe and electric dipole moment in the CP-violating NMSSM

In this work, we make the first study of electroweak baryogenesis(EWBG) based on the LHC data in the CP-violating next-to-minimal supersymmetric model(NMSSM) where a strongly first order electroweak phase transition(EWPT) is obtained in the general complex Higgs potential. With representative benchmark points which pass the current LEP and LHC constraints, we demonstrate the structure of EWPT for those points and how a strongly first order EWPT is obtained in the complex NMSSM where the resulting gravitational wave production properties are found to be within the reaches of future space-based interferometers like BBO and Ultimate-DECIGO. We further calculate the generated baryon asymmetries where the CP violating sources are(1): higgsino-singlino dominated,(2): higgsino-gaugino dominated or(3): from both sources. It is shown that all three representing scenarios could evade the strong constraints set by various electric dipole moments(EDM) searches where cancellations among the EDM contributions occur at the tree level(higgsino-singlino dominated) or loop level(higgsino-gaugino dominated).The 125 GeV SM like Higgs can be either the second lightest neutral Higgs H_2 or the third lightest neutral Higgs H_3. Finally, we comment on the future direct and indirect probe of CPV in the Higgs sector from the collider and EDM experiments.

Measurement of H→μ^+μ^-production in association with a Z boson at the CEPC

The Circular Electron-Positron Collider(CEPC) is a future Higgs factory proposed by the Chinese high energy physics community. It is planned to operate at a center-of-mass energy of 240–250 Ge V and is expected to accumulate an integrated luminosity of 5 ab^(-1) over ten years of operation. At the CEPC, Higgs bosons will be dominantly produced from the ZH associated process. The vast number of Higgs events collected will enable precise studies of its properties, including Yukawa couplings to massive particles. With GEANT4-based simulation of detector effects, we study the feasibility of measuring the Higgs boson decaying into a pair of muons at the CEPC.The results with and without information from the Z boson decay products are provided, showing that a signal significance of over 10 standard deviations can be achieved and the H-μ-μ coupling can be measured within 10%accuracy.

Gluon-pair-creation production model of strong interaction vertices

By studying theηc exclusive decay to double glueballs,we introduce a model to phenomenologically mimic the gluon-pair-vacuum interaction vertices,namely the 0^++model.Based on this model,we study glueball production in pseudoscalar quarkonium decays,explicitlyηc→f0(1500)η(1405),ηb→f0(1500)η(1405),andηb→f0(1710)η(1405)processes.Among them f0(1500)and f0(1710)are well-known scalars possessing large glue components,whileη(1405)is a potential candidate for a pseudoscalar glueball.The preliminary calculation results indicate that these processes are marginally accessible in the presently running experiments BES III,BELLE II,and LHCb.

Maximum relative entropy of coherence for quantum channels

Based on the resource theory for quantifying the coherence of quantum channels, we introduce a new coherence quantifier for quantum channels via maximum relative entropy. We prove that the maximum relative entropy for coherence of quantum channels is directly related to the maximally coherent channels under a particular class of superoperations, which results in an operational interpretation of the maximum relative entropy for coherence of quantum channels. We also introduce the conception of subsuperchannels and sub-superchannel discrimination. For any quantum channels, we show that the advantage of quantum channels in sub-superchannel discrimination can be exactly characterized by the maximum relative entropy of coherence for quantum channels. Similar to the maximum relative entropy of coherence for channels, the robustness of coherence for quantum channels has also been investigated. We show that the maximum relative entropy of coherence for channels provides new operational interpretations of robustness of coherence for quantum channels and illustrates the equivalence of the dephasing-covariant superchannels,incoherent superchannels, and strictly incoherent superchannels in these two operational tasks.

Erratum and Addendum:Gravitational Waves,baryon asymmetry of the universe and electric dipole moment in the CP-violating NMSSM(Chin.Phys.C,42(9):093106(2018))

This paper was published online on 6 August 2018 with the acknowledgement of an author being missed.The acknowledgement of the last author,Jing Shu,should be added as“The work of JS is supported by the National Natural Science Foundation of China under grant No.11647601,No.11690022 and No.11675243 and also supported by the Strategic Priority Research Program of the Chinese Academy of Sciences under grant No.XDB21010200 and No.XDB23030100.Part of the results described in this paper are obtained on the HPC Cluster of SKLTP/ITP?CAS.”.

Gravitational wave imprint of new symmetry breaking

It is believed that there are more fundamental gauge symmetries beyond those described by the Standard Model of particle physics.The scales of these new gauge symmetries are usually too high to be reachable by particle colliders.Considering that the phase transition(PT)relating to the spontaneous breaking of new gauge symmetries to the electroweak symmetry might be strongly first order,we propose considering the stochastic gravitational waves(GW)arising from this phase transition as an indirect way of detecting these new fundamental gauge symmetries.As an illustration,we explore the possibility of detecting the stochastic GW generated from the PT of B−L in the space-based interferometer detectors.Our study demonstrates that the GW energy spectrum is reachable by the LISA,Tianqin,Taiji,BBO,and DECIGO experiments only for the case where the spontaneous breaking of B−L is triggered by at least two electroweak singlet scalars.

Standard model effective field theory from on-shell amplitudes

We present a general method of constructing unfactorizable on-shell amplitudes(amplitude basis) and build up their one-to-one correspondence to the independent and complete operator basis in effective field theory(EFT).We apply our method to the Standard Model EFT and identify the amplitude basis in dimensions 5 and 6,which correspond to the Weinberg operator and operators in the Warsaw basis,except for some linear combinations.

NLO QCD corrections to η_c+h_c(1P)/ψ_(1,2)(1D) production at B-factories

We calculate the next-to-leading order(NLO) quantum chromodynamics(QCD) corrections to double charmonium production processes e+e-→γ*→ηc+hc(1P)/ψ1,2(1D) within the non-relativistic QCD(NRQCD)factorization framework. We find that the corrections to ηc+hc(1P) production are positive, while those to ηc+ψ1,2(1D)are negative. Unlike the J/ψ+ηc case, all the corrections here are not large. Uncertainties in the renormalization scale, quark mass and running energy of center-of-mass are discussed, and the scale dependence of these processes is found to be greatly reduced with the NLO QCD corrections.

X(16.7) as the solution of the NuTeV anomaly

A recent experimental study of excited8 Be decay to its ground state revealed an anomaly in the angular distribution of the final states. This exceptional result is attributed to a new vector gauge boson X(16.7). We study the significance of this new boson, especially its effect in anomalies observed in long-lasting experimental measurements.By comparing the discrepancies between the Standard Model predictions and the experimental results, we find the values and regions of the couplings of X(16.7) to the muon and muon neutrino. In this work, we find that the newly observed boson X(16.7) may be the solution of both the Nu Te V anomaly and the(g-2)_μ puzzle.

Leptonic Decays of Heavy Vector and Pseudoscalar Mesons

Pure leptonic decays of D~*0)(B_^(*s),B_d~*)→l^+l^- and D^(±*)(D_s~*,B^(*+),B_c~*)→lν_l are investigated.The hadronic contributions such as D^0→D^(*0)γ→μ^+μ^- are also explored.We then obtain the updated branching fractions of the pseudoscalar mesons to lepton pairs are modified by a factor of few percentages.Specifically,the Br(B+→e^+ν_e)is reduced by a factor 13%.

Stochastic ravitational wave background from PBH-ABH mergers

The measurement of gravitational waves produced by binary black-hole mergers at the Advanced LIGO has encouraged extensive studies on the stochastic gravitational wave background. Recent studies have focused on gravitational wave sources made of the same species, such as mergers from binary primordial black holes or those from binary astrophysical black holes. In this paper, we study a new possibility - the stochastic gravitational wave background produced by mergers of one primordial black hole and one astrophysical black hole. Such systems are necessarily present if primordial black holes exist. We study the isotropic gravitational wave background produced through the history of the universe. We find it is very challenging to detect such a signal. We also demonstrate that it is improper to treat the gravitational waves produced by such binaries in the Milky Way as a directional stochastic background due to a very low binary formation rate.

On-shell mediator dark matter models and the Xenon1T excess

We present a dark matter model to explain the excess events in the electron recoil data recently reported by the Xenon1 T experiment. In our model, dark matter χ annihilates into a pair of on-shell particles Φ, which subsequently decay into the ψψ final state;ψ interacts with electrons to generate the observed excess events. Because of the mass hierarchy, the velocity of ψ can be rather large and can have an extended distribution, providing a good fit to the electron recoil energy spectrum. We estimate the flux of ψ from dark matter annihilations in the galaxy and further determine the interaction cross section, which is sizable but sufficiently small to allow ψ to penetrate the rocks to reach the underground labs.