The littlest Higgs model with T-parity, which is called LHT model, predicts the existence of the new particles, such as heavy top quarks, heavy gauge bosons, and mirror fermions. We calculate the one-loop contribution...The littlest Higgs model with T-parity, which is called LHT model, predicts the existence of the new particles, such as heavy top quarks, heavy gauge bosons, and mirror fermions. We calculate the one-loop contributions of these new particles to the top quark ehromomagnetic dipole moment （CMDM） AK. We find that the contribution of the LHT model is one order of magnitude smaller than the standard model prediction value.展开更多
In this study,we investigated the anomalous Chromomagnetic Dipole Moment(CMDM),denoted as μ_(q)^(BLHM),of light quarks q=(u,c,d,s,b) within the framework of the Bestest Little Higgs Model(BLHM)as an extension of the ...In this study,we investigated the anomalous Chromomagnetic Dipole Moment(CMDM),denoted as μ_(q)^(BLHM),of light quarks q=(u,c,d,s,b) within the framework of the Bestest Little Higgs Model(BLHM)as an extension of the Standard Model(SM).Our investigation encompassed novel interactions among the light quarks,heavy quark B,and heavy bosons (W'^(±),H^(±),φ^(±),η^(±))incorporating the extended Cabibbo-Kobayashi-Maskawa(CKM)matrix characteristic of the BLHM.We thoroughly explored the permissible parameter space,yielding a spectrum of CMDM values ranging from 10^(-10) to 10^(-3).展开更多
In the framework of the improved chromomagnetic interaction model,we complete a systematic study of the S-wave tetraquark states QqQq(Q=c,b,and q=u,d,s)with different quantum numbers:J^(PC)=0^(+(+)),1^(+(±)),and ...In the framework of the improved chromomagnetic interaction model,we complete a systematic study of the S-wave tetraquark states QqQq(Q=c,b,and q=u,d,s)with different quantum numbers:J^(PC)=0^(+(+)),1^(+(±)),and 2^(+(+)).The mass spectra of tetraquark states are predicted,and the possible decay channels are analyzed by considering both the angular momentum and C-parity conservation.The recently observed hidden-charm tetraquark states with strangeness,such as Z_(cs)(3985)^(-),X(3960),and Z_(cs)(4220)^(+),can be well explained in our model.Additionally,according to the wave function of each tetraquark state,we find that the low-lying states of each QqQq configuration have a large overlap to the QQ and qq meson basis,instead of the Qq and qQ meson basis.This indicates that one can search these tetraquark states in future experiments via the channel of QQ and qq mesons.展开更多
The one-loop contributions to the chromomagnetic dipole momentˆμt(q2)and electric dipole momentˆd t(q2)of the top quark are calculated within the reduced 331 model(RM331)for non-zero q2.It is argued that the results ...The one-loop contributions to the chromomagnetic dipole momentˆμt(q2)and electric dipole momentˆd t(q2)of the top quark are calculated within the reduced 331 model(RM331)for non-zero q2.It is argued that the results are gauge independent and thus represent valid observable quantities.In the RM331,ˆμt(q2)receives new contributions from two heavy gauge bosons,namely Z′and V±,and one neutral scalar boson h2,along with a new contribution from the standard model's Higgs boson via flavor changing neutral currents.The latter,which is also mediated by the Z′gauge boson and the scalar boson h2,can provide a non-vanishingˆd t(q2)if there is a CP-violating phase.The analytical results are presented in terms of both Feynman parameter integrals and Passarino-Veltman scalar functions,which are useful to cross-check the numerical results.Bothˆμt(q2)andˆd t(q2)are numerically evaluated for parameter values still allowed by the constraints from experimental data.It is found that the new one-loop contributions of the RM331 to the real(imaginary)part ofˆμt(q2)are of the order of 10−5(10−6),which means at least three orders of magnitude smaller than the standard model prediction but larger than the predictions of other models of new physics.In the RM331,the dominant contribution arises from the V±gauge boson for‖q‖in the 30-1000 GeV interval and a mass mV of the order of a few hundreds of GeV.As forˆd t(q2),it receives its largest contribution from h2 exchange and can reach values of the order of 10−19,i.e.,smaller than the contributions predicted by other standard model extensions.展开更多
Using an extended chromomagnetic model,we perform a systematic study of the masses of doubly heavy tetraquarks.We find that the ground states of the doubly heavy tetraquarks are dominated by the color-triplet ■config...Using an extended chromomagnetic model,we perform a systematic study of the masses of doubly heavy tetraquarks.We find that the ground states of the doubly heavy tetraquarks are dominated by the color-triplet ■configuration,which is opposite to that of fully heavy tetraquarks.The combined results suggest that the color-triplet configuration becomes more important when the mass difference between the quarks and antiquarks increases.We find three stable states that lie below the thresholds of two pseudoscalar mesons.They are the I^(P)=01^(+)nnbb tetraquark,I^(P)=1^(+)nncb tetraquark,and J^(P)=1^(+)nsbb tetraquark.展开更多
We calculate the masses of the QQqq(Q=c,b:q=u,d,s)tetraquark states with the aid of heavy diquark-antiquark symmetry(HDAS)and the chromomagnetic interaction(CMI)model.The masses of the highestspin(J=2)tetraquarks that...We calculate the masses of the QQqq(Q=c,b:q=u,d,s)tetraquark states with the aid of heavy diquark-antiquark symmetry(HDAS)and the chromomagnetic interaction(CMI)model.The masses of the highestspin(J=2)tetraquarks that have only the(QQ)(3):(qq)_(3).color structure are related with those of conventional hadrons using HDAS.Thereafter,the masses of their partner states are determined with the mass splittings in the CMI model.Our numerical results reveal that(i)the lightest ccnn(n=u,d)is an I(J^(P))=0(1^(+))state around 3929 MeV(53 MeV above the DD^(*) threshold),and none of the double-charm tetraquarks are stable;(ii)the stable double-bottom tetraquarks are the lowest 0(1^(+))bbin around 10488 MeV(≈116 MeV below the BB^(*)threshold)and the lowest 1/2(1^(+))bbns around 10671 MeV(≈20 MeV below the BB_(s)^(*)/B_(s)B^(*)threshold);and(iii)the two lowest bcnn tetraquarks,namely the lowest 0(0^(+))around 7167 MeV and the lowest 0(1)around 7223 MeV,are in the nearthreshold states.Moreover,we discuss the constraints on the masses of double-heavy hadrons.Specifically,for the lowest nonstrange tetraquarks,we obtain T_(cc)<3965 MeV,T_(bb)<10627 MeV,and T_(bc)<7199 MeV.展开更多
New vectorlike quarks have been proposed in many scenarios of new physics beyond the Standard Model,which address the hierarchy problem and may be potentially discovered at the Large Hadron Collider(LHC).Based on a mo...New vectorlike quarks have been proposed in many scenarios of new physics beyond the Standard Model,which address the hierarchy problem and may be potentially discovered at the Large Hadron Collider(LHC).Based on a model-independent framework,we propose to search for the vectorlike B-quark(VLQ-B)and focus on resonant production via b-gluon fusion through chromomagnetic interactions.We then explore the possible signals of the VLQ-B through the B→tW decay mode at the 14 TeV LHC.After a rapid simulation of signal and background events,the 2σ excluded regions and the 5σdiscovery reach in the parameter plane of k_(B)-M_(B)are obtained at the LHC with an integrated luminosity of 300(3000)fb^(-1)in the dilepton final states.展开更多
基金supported in part by the Program for New Century Excellent Talents in Universities under Grant No.NCET-04-0290National Natural Science Foundation of China under Grant No.10675057
文摘The littlest Higgs model with T-parity, which is called LHT model, predicts the existence of the new particles, such as heavy top quarks, heavy gauge bosons, and mirror fermions. We calculate the one-loop contributions of these new particles to the top quark ehromomagnetic dipole moment （CMDM） AK. We find that the contribution of the LHT model is one order of magnitude smaller than the standard model prediction value.
文摘In this study,we investigated the anomalous Chromomagnetic Dipole Moment(CMDM),denoted as μ_(q)^(BLHM),of light quarks q=(u,c,d,s,b) within the framework of the Bestest Little Higgs Model(BLHM)as an extension of the Standard Model(SM).Our investigation encompassed novel interactions among the light quarks,heavy quark B,and heavy bosons (W'^(±),H^(±),φ^(±),η^(±))incorporating the extended Cabibbo-Kobayashi-Maskawa(CKM)matrix characteristic of the BLHM.We thoroughly explored the permissible parameter space,yielding a spectrum of CMDM values ranging from 10^(-10) to 10^(-3).
基金supported by the Scientific Research Foundation of Chengdu University of Technology(10912-KYQD2022-09557)supported by the National Natural Science Foundation of China(11890712)supported by the European Union’s Horizon 2020 research and innovation program(824093(STRONG-2020))。
文摘In the framework of the improved chromomagnetic interaction model,we complete a systematic study of the S-wave tetraquark states QqQq(Q=c,b,and q=u,d,s)with different quantum numbers:J^(PC)=0^(+(+)),1^(+(±)),and 2^(+(+)).The mass spectra of tetraquark states are predicted,and the possible decay channels are analyzed by considering both the angular momentum and C-parity conservation.The recently observed hidden-charm tetraquark states with strangeness,such as Z_(cs)(3985)^(-),X(3960),and Z_(cs)(4220)^(+),can be well explained in our model.Additionally,according to the wave function of each tetraquark state,we find that the low-lying states of each QqQq configuration have a large overlap to the QQ and qq meson basis,instead of the Qq and qQ meson basis.This indicates that one can search these tetraquark states in future experiments via the channel of QQ and qq mesons.
文摘The one-loop contributions to the chromomagnetic dipole momentˆμt(q2)and electric dipole momentˆd t(q2)of the top quark are calculated within the reduced 331 model(RM331)for non-zero q2.It is argued that the results are gauge independent and thus represent valid observable quantities.In the RM331,ˆμt(q2)receives new contributions from two heavy gauge bosons,namely Z′and V±,and one neutral scalar boson h2,along with a new contribution from the standard model's Higgs boson via flavor changing neutral currents.The latter,which is also mediated by the Z′gauge boson and the scalar boson h2,can provide a non-vanishingˆd t(q2)if there is a CP-violating phase.The analytical results are presented in terms of both Feynman parameter integrals and Passarino-Veltman scalar functions,which are useful to cross-check the numerical results.Bothˆμt(q2)andˆd t(q2)are numerically evaluated for parameter values still allowed by the constraints from experimental data.It is found that the new one-loop contributions of the RM331 to the real(imaginary)part ofˆμt(q2)are of the order of 10−5(10−6),which means at least three orders of magnitude smaller than the standard model prediction but larger than the predictions of other models of new physics.In the RM331,the dominant contribution arises from the V±gauge boson for‖q‖in the 30-1000 GeV interval and a mass mV of the order of a few hundreds of GeV.As forˆd t(q2),it receives its largest contribution from h2 exchange and can reach values of the order of 10−19,i.e.,smaller than the contributions predicted by other standard model extensions.
基金Supported by the National Natural Science Foundation of China(NSFC)(11975033,12070131001)。
文摘Using an extended chromomagnetic model,we perform a systematic study of the masses of doubly heavy tetraquarks.We find that the ground states of the doubly heavy tetraquarks are dominated by the color-triplet ■configuration,which is opposite to that of fully heavy tetraquarks.The combined results suggest that the color-triplet configuration becomes more important when the mass difference between the quarks and antiquarks increases.We find three stable states that lie below the thresholds of two pseudoscalar mesons.They are the I^(P)=01^(+)nnbb tetraquark,I^(P)=1^(+)nncb tetraquark,and J^(P)=1^(+)nsbb tetraquark.
基金Supported by National Natural Science Foundation of China (11775130, 11775132, 11635009, 11325525, 11875179)Natural Science Foundation of Shandong Province (ZR2016AM16, ZR2017MA002)。
文摘We calculate the masses of the QQqq(Q=c,b:q=u,d,s)tetraquark states with the aid of heavy diquark-antiquark symmetry(HDAS)and the chromomagnetic interaction(CMI)model.The masses of the highestspin(J=2)tetraquarks that have only the(QQ)(3):(qq)_(3).color structure are related with those of conventional hadrons using HDAS.Thereafter,the masses of their partner states are determined with the mass splittings in the CMI model.Our numerical results reveal that(i)the lightest ccnn(n=u,d)is an I(J^(P))=0(1^(+))state around 3929 MeV(53 MeV above the DD^(*) threshold),and none of the double-charm tetraquarks are stable;(ii)the stable double-bottom tetraquarks are the lowest 0(1^(+))bbin around 10488 MeV(≈116 MeV below the BB^(*)threshold)and the lowest 1/2(1^(+))bbns around 10671 MeV(≈20 MeV below the BB_(s)^(*)/B_(s)B^(*)threshold);and(iii)the two lowest bcnn tetraquarks,namely the lowest 0(0^(+))around 7167 MeV and the lowest 0(1)around 7223 MeV,are in the nearthreshold states.Moreover,we discuss the constraints on the masses of double-heavy hadrons.Specifically,for the lowest nonstrange tetraquarks,we obtain T_(cc)<3965 MeV,T_(bb)<10627 MeV,and T_(bc)<7199 MeV.
基金Supported by the Foundation of the Key Research Projects in Universities of Henan(22A140019)the Natural Science Foundation of Henan Province(222300420443)the Project of Innovation and Entrepreneurship Training for College Students in Henan Province(S202110478024)。
文摘New vectorlike quarks have been proposed in many scenarios of new physics beyond the Standard Model,which address the hierarchy problem and may be potentially discovered at the Large Hadron Collider(LHC).Based on a model-independent framework,we propose to search for the vectorlike B-quark(VLQ-B)and focus on resonant production via b-gluon fusion through chromomagnetic interactions.We then explore the possible signals of the VLQ-B through the B→tW decay mode at the 14 TeV LHC.After a rapid simulation of signal and background events,the 2σ excluded regions and the 5σdiscovery reach in the parameter plane of k_(B)-M_(B)are obtained at the LHC with an integrated luminosity of 300(3000)fb^(-1)in the dilepton final states.
