The potential of muon colliders opens up new possibilities for the exploration of new physics beyond the Standard Model.It is worthwhile to investigate whether muon colliders are suitable for studying gluonic quartic ...The potential of muon colliders opens up new possibilities for the exploration of new physics beyond the Standard Model.It is worthwhile to investigate whether muon colliders are suitable for studying gluonic quartic gauge couplings(gQGCs),which can be contributed by dimension-8 operators in the framework of the Standard Model effective field theory,and are intensively studied recently.In this paper,we study the sensitivity of the processμ^(+)μ^(-)→jjν■to gQGCs.Our results indicate that the muon colliders with c.m.energies larger than 4 TeV can be more sensitive to gQGCs than the Large Hadron Collider.展开更多
Neutral triple gauge couplings(nTGCs)are absent in the Standard Model(SM)and at the dimension-6 level in the Standard Model Effective Field Theory(SMEFT),arising first from dimension-8 operators.As such,they provide a...Neutral triple gauge couplings(nTGCs)are absent in the Standard Model(SM)and at the dimension-6 level in the Standard Model Effective Field Theory(SMEFT),arising first from dimension-8 operators.As such,they provide a unique window for probing new physics beyond the SM.These dimension-8 operators can be mapped to nTGC form factors whose structure is consistent with the spontaneously-broken electroweak gauge symmetry of the SM.In this work,we study the probes of nTGCs in the reaction e^(+)e^(-)→Z_(γ)with Z→l^(+)l^(-)(l=e,μ)at an e^(+)e^(-)collider.We perform a detector-level simulation and analysis of this reaction at the Circular Electron Positron Collider(CEPC)with collision energy√s=240 GeV and an integrated luminosity of 20 ab−1.We present the sensitivity limits on probing the new physics scales of dimension-8 nTGC operators via measurements of the corresponding nTGC form factors.展开更多
Over the last few years,an increasing amount of attention has been devoted to the future of high energy physics.Notably,the nature of the next major collider project after the Large Hadron Collider(LHC)has been a key ...Over the last few years,an increasing amount of attention has been devoted to the future of high energy physics.Notably,the nature of the next major collider project after the Large Hadron Collider(LHC)has been a key subject of extensive discussions.It is becoming increasingly likely that this next project will take the form of a high-energy electron-positron collider operating at a number of centre of mass energies including the Z-pole,near the ZH production threshold,the tt¯threshold and beyond.Several such programmes have been proposed including the CEPC,FCC-ee,ILC,and CLIC.Besides producing the next generation of electroweak(EW)precision measurements and delivering a suite of measurements characterising the properties of the Higgs boson,the clean experimental environment of such colliders has the potential to search for indirect signs of new physics residing at the multi-TeV scale.展开更多
We study the CP-violating(CPV)neutral triple gauge couplings(nTGCs)that can be realized via dimension-8 operators in the Standard Model Effective Field Theory(SMEFT).We present a new formulation of the CPV nTGC form f...We study the CP-violating(CPV)neutral triple gauge couplings(nTGCs)that can be realized via dimension-8 operators in the Standard Model Effective Field Theory(SMEFT).We present a new formulation of the CPV nTGC form factors that is compat-ible with the spontaneous breaking of the electroweak gauge symmetry,and show how these CPV form factors can be matched consistently with the corresponding dimension-8 CPV nTGC operators in the broken phase.We then study probes of the CPV nTGCs at future high-energy e^(+)e^(−)colliders with centre-of-mass energies√s=0.25,0.5,1,3,5 TeV,respectively,demonstrating that the e■beam polarizations can help to improve the sensitivities of probes of the nTGCs.We estimate that the sensitivity reaches for probing the new physics scales of nTGCs can range from O(TeV)at a 250 GeV e^(+)e^(−)collider to O(10 TeV)at an e^(+)e^(−)collider of energy 3-5 TeV,and that the sensitivities to the nTGC form factors vary from O(10^(−4))to O(10^(−6)-10^(−8))for the e^(+)e^(−)collision energy from 250 GeV to 3-5 TeV.展开更多
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...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.展开更多
Vector boson scattering at the Large Hadron Collider(LHC)is sensitive to anomalous quartic gauge couplings(aQGCs).In this study,we investigate the aQGC contribution to Wγjj production at the LHC with√s=13 TeV in the...Vector boson scattering at the Large Hadron Collider(LHC)is sensitive to anomalous quartic gauge couplings(aQGCs).In this study,we investigate the aQGC contribution to Wγjj production at the LHC with√s=13 TeV in the context of an effective field theory(EFT).The unitarity bound is applied as a cut on the energy scale of this production process,which is found to have significant suppressive effects on signals.To enhance the statistical significance,we analyze the kinematic and polarization features of the aQGC signals in detail.We find that the polarization effects induced by aQGCs are unique and can discriminate the signals from the SM backgrounds well.With the proposed event selection strategy,we obtain the constraints on the coefficients of dimension-8 operators with current luminosity.The results indicate that the process pp→Wγjj is powerful for searching for the OM2,3,4,5 and OT5,6,7 operators.展开更多
The article[1]discusses systematically the measurement of neutral triple gauge boson couplings(nTGCs)[2-11](that violate CP symmetry)at high-energy colliders,especially at the electron-positron Higgs factories.Since d...The article[1]discusses systematically the measurement of neutral triple gauge boson couplings(nTGCs)[2-11](that violate CP symmetry)at high-energy colliders,especially at the electron-positron Higgs factories.Since direct couplings of triple neutral gauge bosons do not exist both in the dimension-4 Lagrangian of the standard model(SM)and at the dimension-6 level of the SM effective field theory(SMEFT),measuring the nTGCs can provide an effective window for searching new physics beyond the SM.Furthermore,the nTGCs can provide possible new source of CP violations beyond the Kobayashi-Maskawa(KM)mechanism[12]of the SM.Hence,measuring the CPV nTGCs is important for a better understanding of the CP violations and possibly the origin of the matter in the Universe.展开更多
The standard model(SM)of particle physics has been surprsingly successful in explaining fundamental interactions,yet it leaves many key problems unsolved,including such as the origin of CP violation,the origin of matt...The standard model(SM)of particle physics has been surprsingly successful in explaining fundamental interactions,yet it leaves many key problems unsolved,including such as the origin of CP violation,the origin of matter-antimatter asymmetry in the Universe[1-3],the anomalous magnetic and electric dipole moments of the tau lepton[4,5],as well as a possible neutrionless doubleβdecay process[6-10],etc.The new physics beyond the SM can be systematically formulated via the SM effective field theory(SMEFT)[11]in terms of gauge-invariant effective operators having mass-dimensions higher than four.The neutral triple gauge boson couplings(nTGCs)[12-22]describe interactions among neutral electroweak gauge bosons(Z,γ).They are absent both in the SM and at the level of dimension-6 effective operators of the SMEFT,but can first appear as the dimension-8 effective operators,providing a distinctive window for new physics beyond the SM.展开更多
The Z Zγtriple neutral gauge couplings are absent in the Standard Model(SM)at the tree level.They receive no contributions from dimension-6 effective operators,but can arise from effective operators of dimension-8.We...The Z Zγtriple neutral gauge couplings are absent in the Standard Model(SM)at the tree level.They receive no contributions from dimension-6 effective operators,but can arise from effective operators of dimension-8.We study the scale of new physics associated with such dimension-8 operators that can be probed by measuring the reaction e^+e^-→Zγ followed by Z→■■,vv decays,at future e^+e^- colliders including the CEPC,FCC-ee,ILC and CLIC.We demonstrate how angular distributions of the final-state mono-photon and leptons can play a key rôle in suppressing SM backgrounds.We further demonstrate that using electron/positron beam polarizations can significantly improve the signal sensitivities.We find that the dimension-8 new physics scale can be probed up to the multiTeV region at such lepton colliders.展开更多
We propose a new model with flavor-dependent gauged U(1)B-L1×U(1)B-L2-L3symmetry in addition to the flavor-blind symmetry in the Standard Model. The model contains three right-handed neutrinos to cancel gauge ano...We propose a new model with flavor-dependent gauged U(1)B-L1×U(1)B-L2-L3symmetry in addition to the flavor-blind symmetry in the Standard Model. The model contains three right-handed neutrinos to cancel gauge anomalies and several Higgs bosons to construct the measured fermion masses. We show the generic features of the model and explore its phenomenology. In particular, we discuss the current bounds on the extra gauge bosons from the K and B meson mixings as well as the LEP and LHC data, and focus on their contributions to the lepton flavor violating processes of ?i+1→?iγ(i=1,2).展开更多
基金supported in part by the National Natural Science Foundation of China under Grants Nos.11905093 and 12147214the Natural Science Foundation of the Liaoning Scientific Committee No.LJKZ0978.
文摘The potential of muon colliders opens up new possibilities for the exploration of new physics beyond the Standard Model.It is worthwhile to investigate whether muon colliders are suitable for studying gluonic quartic gauge couplings(gQGCs),which can be contributed by dimension-8 operators in the framework of the Standard Model effective field theory,and are intensively studied recently.In this paper,we study the sensitivity of the processμ^(+)μ^(-)→jjν■to gQGCs.Our results indicate that the muon colliders with c.m.energies larger than 4 TeV can be more sensitive to gQGCs than the Large Hadron Collider.
文摘Neutral triple gauge couplings(nTGCs)are absent in the Standard Model(SM)and at the dimension-6 level in the Standard Model Effective Field Theory(SMEFT),arising first from dimension-8 operators.As such,they provide a unique window for probing new physics beyond the SM.These dimension-8 operators can be mapped to nTGC form factors whose structure is consistent with the spontaneously-broken electroweak gauge symmetry of the SM.In this work,we study the probes of nTGCs in the reaction e^(+)e^(-)→Z_(γ)with Z→l^(+)l^(-)(l=e,μ)at an e^(+)e^(-)collider.We perform a detector-level simulation and analysis of this reaction at the Circular Electron Positron Collider(CEPC)with collision energy√s=240 GeV and an integrated luminosity of 20 ab−1.We present the sensitivity limits on probing the new physics scales of dimension-8 nTGC operators via measurements of the corresponding nTGC form factors.
文摘Over the last few years,an increasing amount of attention has been devoted to the future of high energy physics.Notably,the nature of the next major collider project after the Large Hadron Collider(LHC)has been a key subject of extensive discussions.It is becoming increasingly likely that this next project will take the form of a high-energy electron-positron collider operating at a number of centre of mass energies including the Z-pole,near the ZH production threshold,the tt¯threshold and beyond.Several such programmes have been proposed including the CEPC,FCC-ee,ILC,and CLIC.Besides producing the next generation of electroweak(EW)precision measurements and delivering a suite of measurements characterising the properties of the Higgs boson,the clean experimental environment of such colliders has the potential to search for indirect signs of new physics residing at the multi-TeV scale.
基金The work of John Ellis was supported in part by the United Kingdom STFC(Grant No.ST/T000759/1)The work of Hong-Jian He and Rui-Qing Xiao were supported in part by the National Natural Science Foundation of China(Grant Nos.12175136,and 12435005)+4 种基金the Shenzhen Science and Technology Program(Grant No.JCYJ20240813150911015)the State Key Laboratory of Dark Matter Physics,the Key Laboratory for Particle Astrophysics and Cosmology(MOE)the Shanghai Key Laboratory for Particle Physics and Cosmology.Rui-Qing Xiao is also supported in part by the National Science Foundation of China(Grant Nos.12175006,12188102,and 12061141002)the Ministry of Science and Technology of China(Grant No.2023YFA1605800)the State Key Laboratory of Nuclear Physics and Technology.
文摘We study the CP-violating(CPV)neutral triple gauge couplings(nTGCs)that can be realized via dimension-8 operators in the Standard Model Effective Field Theory(SMEFT).We present a new formulation of the CPV nTGC form factors that is compat-ible with the spontaneous breaking of the electroweak gauge symmetry,and show how these CPV form factors can be matched consistently with the corresponding dimension-8 CPV nTGC operators in the broken phase.We then study probes of the CPV nTGCs at future high-energy e^(+)e^(−)colliders with centre-of-mass energies√s=0.25,0.5,1,3,5 TeV,respectively,demonstrating that the e■beam polarizations can help to improve the sensitivities of probes of the nTGCs.We estimate that the sensitivity reaches for probing the new physics scales of nTGCs can range from O(TeV)at a 250 GeV e^(+)e^(−)collider to O(10 TeV)at an e^(+)e^(−)collider of energy 3-5 TeV,and that the sensitivities to the nTGC form factors vary from O(10^(−4))to O(10^(−6)-10^(−8))for the e^(+)e^(−)collision energy from 250 GeV to 3-5 TeV.
基金supported in part by United Kingdom STFC(Grant No.ST/P000258/1)in part by the Estonian Research Council via a Mobilitas Pluss grant+5 种基金in part by the TDLI distinguished visiting fellow programmesupported in part by the National Natural Science Foundation of China(Grant Nos.11675086,and 11835005)supported in part by the CAS Center for Excellence in Particle Physics(CCEPP)the National Key R&D Program of China(Grant No.2017YFA0402204)the Key Laboratory for Particle Physics,Astrophysics and Cosmology(Ministry of Education)the Office of Science and Technology,Shanghai Municipal Government(Grant No.16DZ2260200)。
文摘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.
基金Supported in part by the National Natural Science Foundation of China (11905093, 11875157, 11947402)the Doctoral Start-up Foundation of Liaoning Province (2019-BS-154)
文摘Vector boson scattering at the Large Hadron Collider(LHC)is sensitive to anomalous quartic gauge couplings(aQGCs).In this study,we investigate the aQGC contribution to Wγjj production at the LHC with√s=13 TeV in the context of an effective field theory(EFT).The unitarity bound is applied as a cut on the energy scale of this production process,which is found to have significant suppressive effects on signals.To enhance the statistical significance,we analyze the kinematic and polarization features of the aQGC signals in detail.We find that the polarization effects induced by aQGCs are unique and can discriminate the signals from the SM backgrounds well.With the proposed event selection strategy,we obtain the constraints on the coefficients of dimension-8 operators with current luminosity.The results indicate that the process pp→Wγjj is powerful for searching for the OM2,3,4,5 and OT5,6,7 operators.
文摘The article[1]discusses systematically the measurement of neutral triple gauge boson couplings(nTGCs)[2-11](that violate CP symmetry)at high-energy colliders,especially at the electron-positron Higgs factories.Since direct couplings of triple neutral gauge bosons do not exist both in the dimension-4 Lagrangian of the standard model(SM)and at the dimension-6 level of the SM effective field theory(SMEFT),measuring the nTGCs can provide an effective window for searching new physics beyond the SM.Furthermore,the nTGCs can provide possible new source of CP violations beyond the Kobayashi-Maskawa(KM)mechanism[12]of the SM.Hence,measuring the CPV nTGCs is important for a better understanding of the CP violations and possibly the origin of the matter in the Universe.
文摘The standard model(SM)of particle physics has been surprsingly successful in explaining fundamental interactions,yet it leaves many key problems unsolved,including such as the origin of CP violation,the origin of matter-antimatter asymmetry in the Universe[1-3],the anomalous magnetic and electric dipole moments of the tau lepton[4,5],as well as a possible neutrionless doubleβdecay process[6-10],etc.The new physics beyond the SM can be systematically formulated via the SM effective field theory(SMEFT)[11]in terms of gauge-invariant effective operators having mass-dimensions higher than four.The neutral triple gauge boson couplings(nTGCs)[12-22]describe interactions among neutral electroweak gauge bosons(Z,γ).They are absent both in the SM and at the level of dimension-6 effective operators of the SMEFT,but can first appear as the dimension-8 effective operators,providing a distinctive window for new physics beyond the SM.
基金The work of JE was supported in part by United Kingdom STFC Grant ST/P000258/1in part by the Estonian Research Council via a Mobilitas Pluss grant+5 种基金in part by the TDLI distinguished visiting fellow programmeThe work of HJH and RQX was supported in part by the National NSF of China(11675086,11835005)HJH is also supported in part by the CAS Center for Excellence in Particle Physics(CCEPP)the National Key R&D Program of China(2017YFA0402204)the Shanghai Laboratory for Particle Physics and Cosmology(11DZ2260700)the Office of Science and Technology,Shanghai Municipal Government(16DZ2260200)。
文摘The Z Zγtriple neutral gauge couplings are absent in the Standard Model(SM)at the tree level.They receive no contributions from dimension-6 effective operators,but can arise from effective operators of dimension-8.We study the scale of new physics associated with such dimension-8 operators that can be probed by measuring the reaction e^+e^-→Zγ followed by Z→■■,vv decays,at future e^+e^- colliders including the CEPC,FCC-ee,ILC and CLIC.We demonstrate how angular distributions of the final-state mono-photon and leptons can play a key rôle in suppressing SM backgrounds.We further demonstrate that using electron/positron beam polarizations can significantly improve the signal sensitivities.We find that the dimension-8 new physics scale can be probed up to the multiTeV region at such lepton colliders.
基金Supported by National Center for Theoretical Sciences and MoST(MoST-104-2112-M-007-003-MY3 and MoST-107-2119-M-007-013-MY3)supported by the Ministry of Science,ICT and Future Planning,Gyeongsangbuk-do and Pohang City(H.O.)
文摘We propose a new model with flavor-dependent gauged U(1)B-L1×U(1)B-L2-L3symmetry in addition to the flavor-blind symmetry in the Standard Model. The model contains three right-handed neutrinos to cancel gauge anomalies and several Higgs bosons to construct the measured fermion masses. We show the generic features of the model and explore its phenomenology. In particular, we discuss the current bounds on the extra gauge bosons from the K and B meson mixings as well as the LEP and LHC data, and focus on their contributions to the lepton flavor violating processes of ?i+1→?iγ(i=1,2).
