期刊：
Journal of High Energy Physics,2024年(8) ISSN：1029-8479
通讯作者：
Li, XQ
作者机构：
[Chen, Feng-Zhi] Jinan Univ, Coll Phys & Optoelect Engn, Dept Phys, Guangzhou 510632, Peoples R China.;[Chen, Feng-Zhi] Jinan Univ, Coll Phys & Optoelect Engn, Siyuan Lab, Guangzhou 510632, Peoples R China.;[Li, Xin-Qiang; Yang, Ya-Dong; Peng, Shi-Can; Zou, Yuan-He] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Li, Xin-Qiang; Yang, Ya-Dong; Peng, Shi-Can; Zou, Yuan-He] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;[Li, Xin-Qiang] Peking Univ, Ctr High Energy Phys, Beijing 100871, Peoples R China.
通讯机构：
[Li, XQ ] C;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;Peking Univ, Ctr High Energy Phys, Beijing 100871, Peoples R China.
摘要：
In this work, we make a study of the tau(-) -> omega pi(-)nu(tau) decay in the framework of low-energy effective field theory. The JPG decompositions of the quark currents and the omega pi final state show that, besides the Standard Model vector interaction, only the non-standard tensor interaction can have a non-zero contribution to the decay. To discuss its effect, a reliable calculation of the omega pi tensor form factors is necessary. After constructing the Lagrangian of resonance chiral theory with external tensor sources, we calculate both the vector and tensor form factors with the relevant resonance couplings determined by combining the QCD short-distance constraints, the fit to the spectral function of tau(-) -> omega pi(-)nu(tau) decay, as well as the matching between the O(p(4)) odd-intrinsic-parity operators after integrating out the vector resonances and the O(p(6)) operators of chiral perturbation theory. The new physics effect is then investigated in the distributions of the spectral function and the forward-backward asymmetry of tau(-) -> omega pi(-)nu(tau) decay. We find that the spectral function is dominated by the Standard Model, and the non-standard tensor contribution is negligible. However, since the forward-backward asymmetry can be only generated with a non-zero tensor interaction, the observable is quite sensitive to this kind of new physics. A future measurement of the observable at the Belle II experiment as well as at the proposed Tera-Z and STCF facilities is, therefore, strongly called for to check the existence of such a non-standard tensor interaction.
作者机构：
[Li, Xin-Qiang; Wei, Le-Le] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Li, Xin-Qiang; Wei, Le-Le] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;[Li, Xin-Qiang] Peking Univ, Ctr High Energy Phys, Beijing 100871, Peoples R China.;[Lin, Li-Juan; Wang, En] Zhengzhou Univ, Sch Phys, Zhengzhou 450001, Peoples R China.;[Wang, En] Guangxi Normal Univ, Guangxi Key Lab Nucl Phys & Nucl Technol, Guilin 541004, Peoples R China.
通讯机构：
[Li, XQ ] C;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.
摘要：
We study the B- -> K- eta eta(c) decay by taking into account the S-wave contributions from the pseudoscalar meson-pseudoscalar meson interactions within the unitary coupled-channel approach, where the D (D) over bar bound state is dynamically generated. In addition, the contribution from the intermediate resonance K-0(*) (1430)(-), with K-0*(1430)(-) -> K- eta, is also considered. Our results show that there is a clear peak around 3720 MeV in the eta eta(c) invariant mass distribution, which could be associated with the D (D) over bar bound state. The future precise measurements of the B- -> K- eta eta(c) process at the Belle II and LHCb experiments could be, therefore, used to check the existence of the D (D) over bar bound state, and to deepen our understanding of the hadron-hadron interactions.
作者机构：
[Yang, Ya-Dong; Yuan, Xing-Bo; Yuan, XB; Xie, Ze-Jun; Li, Xin-Qiang] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Yang, Ya-Dong; Yuan, Xing-Bo; Yuan, XB; Xie, Ze-Jun; Li, Xin-Qiang] Cent China Normal Univ, Key Lab Quark & Lepton Phys, MOE, Wuhan 430079, Hubei, Peoples R China.;[Li, Xin-Qiang] Peking Univ, Ctr High Energy Phys, Beijing 100871, Peoples R China.;[Yang, Ya-Dong] Henan Normal Univ, Inst Particle & Nucl Phys, Xinxiang 453007, Peoples R China.
通讯机构：
[Yuan, XB ] C;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Key Lab Quark & Lepton Phys, MOE, Wuhan 430079, Hubei, Peoples R China.
摘要：
Motivated by the latest CDF.. -mass measurement as well as the muon.. - 2 anomaly and the discrepancies observed in.......+..- transitions, we propose an extension of the Standard Model (SM) with the.... (2)..-singlet vector-like fermion partners that are featured by additional.. (1)' gauge symmetry. The fermion partners have the same SM quantum numbers as of the righthanded SM fermions, and can therefore mix with the latter after the electroweak and the.. (1)' symmetry breaking. As a result, desirable loop-level corrections to the (.. - 2).., the.. -boson mass.... and the Wilson coefficient.9 in.......+..- transitions can be obtained. The final allowed parameter space is also consistent with the constraints from the.....+.. - decay, the neutrino trident production and the LHC direct searches for the vector-like quarks and leptons.
期刊：
Journal of High Energy Physics,2024年2024(6):1-48 ISSN：1029-8479
通讯作者：
Hou, BF
作者机构：
[Hou, BF; Hou, Biao-Feng; Yang, Ya-Dong; Yuan, Xing-Bo; Li, Xin-Qiang; Shen, Meng] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Hou, BF; Hou, Biao-Feng; Yang, Ya-Dong; Yuan, Xing-Bo; Li, Xin-Qiang; Shen, Meng] Cent China Normal Univ, Key Lab Quark & Lepton Phys, MOE, Wuhan 430079, Hubei, Peoples R China.;[Li, Xin-Qiang] Peking Univ, Ctr High Energy Phys, Beijing 100871, Peoples R China.;[Yang, Ya-Dong] Henan Normal Univ, Inst Particle & Nucl Phys, Xinxiang 453007, Peoples R China.
通讯机构：
[Hou, BF ] C;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Key Lab Quark & Lepton Phys, MOE, Wuhan 430079, Hubei, Peoples R China.
关键词：
New Light Particles;Semi-Leptonic Decays;Flavour Symmetries;SMEFT
摘要：
Recently, the Belle II collaboration announced the first measurement of the branching ratio
$$ \mathcal{B}\left({B}^{+}\to {K}^{+}\nu \overline{\nu}\right) $$
, which is found to be about 2.7σ higher than the Standard Model (SM) prediction. We decipher the data with two new physics scenarios: the underlying quark-level
$$ b\to s\nu \overline{\nu} $$
transition is, besides the SM contribution, further affected by heavy new mediators that are much heavier than the electroweak scale, or amended by an additional decay channel with undetected light final states like dark matter or axion-like particles. These two scenarios can be most conveniently analyzed in the SM effective field theory (SMEFT) and the dark SMEFT (DSMEFT) framework, respectively. We consider the flavour structures of the resulting effective operators to be either generic or satisfy the minimal flavour violation (MFV) hypothesis, both for the quark and lepton sectors. In the first scenario, once the MFV assumption is made, only one SM-like low-energy effective operator induced by the SMEFT dimension-six operators can account for the Belle II excess, whose parameter space is, however, excluded by the Belle upper bound of the branching ratio
$$ \mathcal{B}\left({B}^0\to {K}^{\ast 0}\nu \overline{\nu}\right) $$
. In the second scenario, it is found that the Belle II excess can be accommodated by 22 of the DSMEFT operators involving one or two scalar, fermionic, or vector dark matters as well as axion-like particles. These operators also receive dominant constraints from the B0 → K*0 + inv and Bs → inv decays. Once the MFV hypothesis is assumed, the number of viable operators is reduced to 14, and the B+ → π+ + inv and K+ → π+ + inv decays start to put further constraints on them. Within the parameter space allowed by all the current experimental data, the q2 distributions of the B → K(*) + inv decays are then studied for each viable operator. We find that the resulting prediction of the operator
$$ {\mathcal{Q}}_{q\chi}=\left({\overline{q}}_p{\gamma}_{\mu }{q}_r\right)\left(\overline{\chi}{\gamma}^{\mu}\chi \right) $$
with a fermionic dark matter mass mχ ≈ 700 MeV can closely match the Belle II event distribution in the bins 2 ≤ q2 ≤ 7 GeV2. In addition, we, for the first time, calculate systematically the longitudinal polarization fraction FL of K* in the B → K* + inv decays within the DLEFT. By combining the decay spectra and FL, almost all the DSMEFT operators are found to be distinguishable from each other. Finally, the future prospects at Belle II, CEPC and FCC-ee are also discussed for some of these FCNC processes.
期刊：
Monthly Notices of the Royal Astronomical Society,2023年518(2):2005-2014 ISSN：0035-8711
通讯作者：
Shao-Lin Xiong
作者机构：
[Cai, Ce] Hebei Normal Univ, Coll Phys, Shijiazhuang 050024, Hebei, Peoples R China.;[Cai, Ce] Hebei Normal Univ, Hebei Key Lab Photophys Res & Applicat, Shijiazhuang 050024, Hebei, Peoples R China.;[Zheng, Chao; Cai, Ce; Li, Xin-Qiao; Guo, Zhi-Wei; Liu, Jia-Cong; Zhang, Yan-Qiu; Zhao, Yi; Du, Yan-Qi; Peng, Wen-Xi; Xiong, Shao-Lin; Xue, Wang-Chen; Wang, Ping; Wen, Xiang-Yang; Zhang, Fan; Zhao, Xiao-Yun; Li, Cheng-Kui; Xiao, Shuo; Zheng, Shi-Jie; Xie, Sheng-Lun; Yi, Qi-Bin; Song, Li-Ming] Chinese Acad Sci, Inst High Energy Phys, Key Lab Particle Astrophys, Beijing 100049, Peoples R China.;[Zheng, Chao; Cai, Ce; Liu, Jia-Cong; Zhang, Yan-Qiu; Xue, Wang-Chen; Xiao, Shuo; Zheng, Shi-Jie; Song, Li-Ming] Chinese Acad Sci, Univ Chinese Acad Sci, Beijing 100049, Peoples R China.;[Zhao, Yi] Beijing Normal Univ, Dept Astron, Beijing 100875, Peoples R China.
通讯机构：
[Shao-Lin Xiong] K;Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, China
关键词：
methods: data analysis;gamma-ray burst
摘要：
<jats:title>ABSTRACT</jats:title><jats:p>Searching for X-ray and gamma-ray bursts, including Gamma-ray bursts (GRBs), Soft Gamma-ray Repeaters (SGRs), and high energy transients associated with Gravitational wave (GW) events or Fast radio bursts (FRBs), is of great importance in the multimessenger and multiwavelength era. Although a coherent search based on the likelihood ratio and Gaussian statistics has been established and utilized in many studies, this Gaussian-based method could be problematic for weak and short bursts which usually have very few counts. To deal with all bursts including weak ones, here we propose the coherent search in Poisson statistics. We studied the difference between Poisson-based and Gaussian-based search methods by Monte Carlo simulations, and find that the Poisson-based search method has advantages compared to the Gaussian case, especially for weak bursts. Our results show that, for very weak bursts with very low number of counts, the Poisson-based search can provide higher significance than the Gaussian-based search, and its likelihood ratio (for background fluctuation) still generally follows the χ2 distribution, making the significance estimation of searched bursts very convenient. Thus, we suggest that the coherent search based on Poisson-likelihood ratio is more appropriate in the search for generic transients including very weak ones.</jats:p>
作者机构：
[Yang, Ya-Dong; Li, Shao-Ping; Duan, Wen-Feng; Li, Xin-Qiang] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[Yang, Ya-Dong; Li, Shao-Ping; Duan, Wen-Feng; Li, Xin-Qiang] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;[Yang, Ya-Dong] Henan Normal Univ, Inst Particle & Nucl Phys, Xinxiang 453007, Peoples R China.;[Li, Xin-Qiang] Peking Univ, Ctr High Energy Phys, Beijing 100871, Peoples R China.
通讯机构：
[Li, X.-Q.] I;Institute of Particle Physics, China
关键词：
rare B-meson decays;new physics beyond the SM;Hubble tension;right-handed neutrino
摘要：
<jats:title>Abstract</jats:title>
<jats:p>Updated measurements from the LHCb and SH0ES collaborations have respectively strengthened the deviations of the ratio <jats:inline-formula>
<jats:tex-math><?CDATA $R_{K}$?></jats:tex-math>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_47_3_033102_M1.jpg" xlink:type="simple" />
</jats:inline-formula> in rare semi-leptonic <jats:inline-formula>
<jats:tex-math><?CDATA $B$?></jats:tex-math>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_47_3_033102_M2.jpg" xlink:type="simple" />
</jats:inline-formula>-meson decays and the present-day Hubble parameter <jats:inline-formula>
<jats:tex-math><?CDATA $H_0$?></jats:tex-math>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_47_3_033102_M3.jpg" xlink:type="simple" />
</jats:inline-formula> in the Universe, implying tantalizing hints of new physics beyond the standard model. In this paper, we consider a simple flavor-specific two-Higgs-doublet model, where long-standing <jats:inline-formula>
<jats:tex-math><?CDATA $R_{K^{(*)}}$?></jats:tex-math>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_47_3_033102_M4.jpg" xlink:type="simple" />
</jats:inline-formula> anomalies can be addressed by a one-flavor right-handed neutrino. An intriguing prediction resulting from the parameter space for the <jats:inline-formula>
<jats:tex-math><?CDATA $R_{K^{(*)}}$?></jats:tex-math>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_47_3_033102_M5.jpg" xlink:type="simple" />
</jats:inline-formula> resolution under flavor- and collider-physics constraints points toward a shift in the effective neutrino number, <jats:inline-formula>
<jats:tex-math><?CDATA $\Delta N_{\rm eff}=N_{\rm eff}-N_{\rm eff}^{\rm SM}$?></jats:tex-math>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_47_3_033102_M6.jpg" xlink:type="simple" />
</jats:inline-formula>, as a favored way to ease the <jats:inline-formula>
<jats:tex-math><?CDATA $H_0$?></jats:tex-math>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_47_3_033102_M7.jpg" xlink:type="simple" />
</jats:inline-formula> tension. Depending on whether the neutrino is of the Dirac or Majorana type, we show that the resulting shift is <jats:inline-formula>
<jats:tex-math><?CDATA $\Delta N_{\rm eff}\simeq 1.0$?></jats:tex-math>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_47_3_033102_M8.jpg" xlink:type="simple" />
</jats:inline-formula> for the former case and <jats:inline-formula>
<jats:tex-math><?CDATA $\Delta N_{\rm eff}\simeq 0.5$?></jats:tex-math>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_47_3_033102_M9.jpg" xlink:type="simple" />
</jats:inline-formula> for the latter case. While the Dirac case is disfavored by the CMB polarization measurements, the Majorana solution is consistent with recent studies using a combined dataset from various sources. Consequently, such a simple flavor-specific two-Higgs-doublet model provides a link between <jats:inline-formula>
<jats:tex-math><?CDATA $R_{K^{(*)}}$?></jats:tex-math>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_47_3_033102_M10.jpg" xlink:type="simple" />
</jats:inline-formula> anomalies and <jats:inline-formula>
<jats:tex-math><?CDATA $H_0$?></jats:tex-math>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_47_3_033102_M11.jpg" xlink:type="simple" />
</jats:inline-formula> tension, which in turn can be readily verified or disproved by upcoming measurements.</jats:p>
摘要：
<jats:title>A<jats:sc>bstract</jats:sc>
</jats:title><jats:p>The semitauonic <jats:inline-formula><jats:alternatives><jats:tex-math>$$ {B}_c^{-}\to J/\psi {\tau}^{-}{\overline{\nu}}_{\tau } $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:msubsup>
<mml:mi>B</mml:mi>
<mml:mi>c</mml:mi>
<mml:mo>−</mml:mo>
</mml:msubsup>
<mml:mo>→</mml:mo>
<mml:mi>J</mml:mi>
<mml:mo>/</mml:mo>
<mml:mi>ψ</mml:mi>
<mml:msup>
<mml:mi>τ</mml:mi>
<mml:mo>−</mml:mo>
</mml:msup>
<mml:msub>
<mml:mover>
<mml:mi>ν</mml:mi>
<mml:mo>¯</mml:mo>
</mml:mover>
<mml:mi>τ</mml:mi>
</mml:msub>
</mml:math></jats:alternatives></jats:inline-formula> decay provides an ideal and clean mode to scrutinize possible new physics effects in <jats:inline-formula><jats:alternatives><jats:tex-math>$$ b\to c{\tau}^{-}{\overline{\nu}}_{\tau } $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mi>b</mml:mi>
<mml:mo>→</mml:mo>
<mml:mi>c</mml:mi>
<mml:msup>
<mml:mi>τ</mml:mi>
<mml:mo>−</mml:mo>
</mml:msup>
<mml:msub>
<mml:mover>
<mml:mi>ν</mml:mi>
<mml:mo>¯</mml:mo>
</mml:mover>
<mml:mi>τ</mml:mi>
</mml:msub>
</mml:math></jats:alternatives></jats:inline-formula> transitions as indicated by the current data on <jats:italic>R</jats:italic>(<jats:italic>D</jats:italic><jats:sup>(*)</jats:sup>) anomalies. In this work, we use the spin density matrix method to obtain the maximum information on the underlying physics of <jats:inline-formula><jats:alternatives><jats:tex-math>$$ {B}_c^{-}\to J/\psi {\tau}^{-}{\overline{\nu}}_{\tau } $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:msubsup>
<mml:mi>B</mml:mi>
<mml:mi>c</mml:mi>
<mml:mo>−</mml:mo>
</mml:msubsup>
<mml:mo>→</mml:mo>
<mml:mi>J</mml:mi>
<mml:mo>/</mml:mo>
<mml:mi>ψ</mml:mi>
<mml:msup>
<mml:mi>τ</mml:mi>
<mml:mo>−</mml:mo>
</mml:msup>
<mml:msub>
<mml:mover>
<mml:mi>ν</mml:mi>
<mml:mo>¯</mml:mo>
</mml:mover>
<mml:mi>τ</mml:mi>
</mml:msub>
</mml:math></jats:alternatives></jats:inline-formula> decay with both polarized <jats:italic>τ</jats:italic> lepton and <jats:italic>J/ψ</jats:italic> meson. Their subsequent decays, with <jats:italic>J/ψ → μ</jats:italic><jats:sup>+</jats:sup><jats:italic>μ</jats:italic><jats:sup><jats:italic>−</jats:italic></jats:sup> as well as <jats:italic>τ</jats:italic><jats:sup><jats:italic>−</jats:italic></jats:sup> → <jats:italic>π</jats:italic><jats:sup><jats:italic>−</jats:italic></jats:sup><jats:italic>ν</jats:italic><jats:sub><jats:italic>τ</jats:italic></jats:sub>, <jats:italic>τ</jats:italic><jats:sup><jats:italic>−</jats:italic></jats:sup> → <jats:italic>ρ</jats:italic><jats:sup><jats:italic>−</jats:italic></jats:sup><jats:italic>ν</jats:italic><jats:sub><jats:italic>τ</jats:italic></jats:sub> and <jats:inline-formula><jats:alternatives><jats:tex-math>$$ {\tau}^{-}\to {\ell}^{-}{\overline{\nu}}_{\ell }{\nu}_{\tau } $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:msup>
<mml:mi>τ</mml:mi>
<mml:mo>−</mml:mo>
</mml:msup>
<mml:mo>→</mml:mo>
<mml:msup>
<mml:mi>ℓ</mml:mi>
<mml:mo>−</mml:mo>
</mml:msup>
<mml:msub>
<mml:mover>
<mml:mi>ν</mml:mi>
<mml:mo>¯</mml:mo>
</mml:mover>
<mml:mi>ℓ</mml:mi>
</mml:msub>
<mml:msub>
<mml:mi>ν</mml:mi>
<mml:mi>τ</mml:mi>
</mml:msub>
</mml:math></jats:alternatives></jats:inline-formula>, are exploited to extract the energy and angular distributions of the charged final-state particles in the processes. Starting with the most general effective Hamiltonian relevant for the <jats:inline-formula><jats:alternatives><jats:tex-math>$$ b\to c{\tau}^{-}{\overline{\nu}}_{\tau } $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mi>b</mml:mi>
<mml:mo>→</mml:mo>
<mml:mi>c</mml:mi>
<mml:msup>
<mml:mi>τ</mml:mi>
<mml:mo>−</mml:mo>
</mml:msup>
<mml:msub>
<mml:mover>
<mml:mi>ν</mml:mi>
<mml:mo>¯</mml:mo>
</mml:mover>
<mml:mi>τ</mml:mi>
</mml:msub>
</mml:math></jats:alternatives></jats:inline-formula> transitions, including all possible Lorentz structures of the dimension-six operators with both left- and right-handed neutrinos, we first derive the five-fold differential decay rate in terms of the visible final-state kinematics. From this distribution, we then construct in total 34 normalized observables, among which nine refer to the CP-violating triple product asymmetries that vanish within the Standard Model. We also construct five new observables based on the combinations of these normalized observables that can only be attributed to the right-handed neutrinos. On the other hand, considering the low statistics of the fully differential distribution, we introduce some integrated observables with only one kinematic variable left, which are more promising to be measured due to the largely increased statistics. The sensitivities of all these observables to the different new physics scenarios are investigated in detail. Finally, assuming an ideal circumstance, we give an estimate of the statistical uncertainties of the nine CP-conserving observables at LHCb and found that <jats:italic>τ</jats:italic><jats:sup><jats:italic>−</jats:italic></jats:sup> → <jats:italic>π</jats:italic><jats:sup><jats:italic>−</jats:italic></jats:sup><jats:italic>ν</jats:italic><jats:sub><jats:italic>τ</jats:italic></jats:sub> has the highest analyzing power among the three <jats:italic>τ</jats:italic> decay channels.</jats:p>
作者机构：
[Yang, Ya-Dong; Zheng, Dong-Hui; Kong, Ya-Ru; Li, Xin-Qiang] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Yang, Ya-Dong; Zheng, Dong-Hui; Kong, Ya-Ru; Li, Xin-Qiang] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;[Lai, Li-Fen] Shangrao Normal Univ, Sch Phys & Elect Informat, Shangrao 334001, Peoples R China.;[Li, Xin-Qiang] Peking Univ, Ctr High Energy Phys, Beijing 100871, Peoples R China.;[Yan, Xin-Shuai; Yang, Ya-Dong; Yan, XS] Henan Normal Univ, Inst Particle & Nucl Phys, Xinxiang 453007, Henan, Peoples R China.
通讯机构：
[Yan, XS ] H;Henan Normal Univ, Inst Particle & Nucl Phys, Xinxiang 453007, Henan, Peoples R China.
摘要：
The absence of semitauonic decays of charmed hadrons makes the decay processes mediated by the quark-level c -> d tau thorn nu tau transition inadequate for probing a generic new physics (NP) with all kinds of Dirac structures. To fill in this gap, we consider in this paper the quasielastic neutrino scattering process nu tau thorn n -> tau- thorn Lambda c, and propose searching for NP through the polarizations of the tau lepton and the Lambda c baryon. In the framework of a general low-energy effective Lagrangian, we perform a comprehensive analysis of the (differential) cross sections and polarization vectors of the process both within the Standard Model and in various NP scenarios, and scrutinize possible NP signals. We also explore the influence on our findings due to the uncertainties and the different parametrizations of the Lambda c -> N transition form factors, and show that they have become one of the major challenges to further constrain possible NP through the quasielastic scattering process.
摘要：
<jats:title>Abstract</jats:title><jats:p>“A Craftsman Must Sharpen His Tools to Do His Job,” said Confucius. Nuclear detection and readout techniques are the foundation of particle physics, nuclear physics, and particle astrophysics to reveal the nature of the universe. Also, they are being increasingly used in other disciplines like nuclear power generation, life sciences, environmental sciences, medical sciences, etc. The article reviews the short history, recent development, and trend of nuclear detection and readout techniques, covering Semiconductor Detector, Gaseous Detector, Scintillation Detector, Cherenkov Detector, Transition Radiation Detector, and Readout Techniques. By explaining the principle and using examples, we hope to help the interested reader underst and this research field and bring exciting information to the community.</jats:p>
作者机构：
[Yuan, Xing -Bo; Yang, Ya-Dong; Xie, Ze-Jun; Li, Xin-Qiang] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Yuan, Xing -Bo; Yang, Ya-Dong; Xie, Ze-Jun; Li, Xin-Qiang] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;[Yang, Ya-Dong] Henan Normal Univ, Inst Particle & Nucl Phys, Xinxiang 453007, Henan, Peoples R China.
通讯机构：
[Xing-Bo Yuan] I;Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOE), Central China Normal University, Wuhan, Hubei 430079, China
摘要：
The recently updated measurement of the W-boson mass by the CDF collaboration exhibits a 7cr deviation from the SM expectation, which may imply a sign of new physics beyond the SM. The observed discrepancy could be explained by new fermions that carry the electroweak gauge charges and affect the vacuum polarization of gauge bosons. Notably, if the new fermions also have the same quantum numbers as of the SM quarks, they can mix with the latter and thus modify the penguin diagrams governing the b -> st+t- transitions. Therefore, the W-boson mass shift could be related to the b -> st+t- anomalies observed by the LHCb collaboration during the past few years. To investigate this possibility, we consider in this letter a model containing a vector-like top partner gauged under a new U (1)(gamma) symmetry. It is found that the latest CDF mW measurement and the b -> st+t- anomalies can be simultaneously accommodated at 2cr level.(c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3).
作者：
Zhao, Y.;Liu, J. C.;Xiong, S. L.;Xue, W. C.;Yi, Q. B.;...
期刊：
GEOPHYSICAL RESEARCH LETTERS,2023年50(14) ISSN：0094-8276
通讯作者：
Xiong, SL
作者机构：
[Zhao, Y.; Yu, H.] Beijing Normal Univ, Dept Astron, Beijing, Peoples R China.;[Xiong, S. L.; He, J. J.; Lu, F. J.; Sun, J. C.; Wang, J.; Zhao, Y.; Xue, W. C.; Li, X. Q.; Zhang, Y. Q.; Qiao, R.; Wen, X. Y.; Zhang, B. X.; Xu, Y. B.; Wu, H.; Zhang, P.; Zhang, D. L.; Huang, Y.; Ma, X.; Song, X. Y.; Li, B.; Wang, C. W.; Gao, M.; Sun, X. L.; Li, X. B.; Wang, P.; Gong, K.; Liu, J. C.; Liang, X. H.; Song, L. M.; An, Z. H.; Tan, W. J.; Zheng, S. J.; Zhang, H. M.; Zhang, F.; Li, G.; Yi, Q. B.; Chen, G.; Zheng, C.; Zhang, S. N.; Peng, W. X.; Zhao, X. Y.; Liang, J.; Yang, S.; Liu, Y. Q.; Zhang, Z.; Liao, J. Y.; Wang, J. Z.; Du, Y. Q.; Guo, D. Y.] Chinese Acad Sci, Inst High Energy Phys, Key Lab Particle Astrophys, Beijing, Peoples R China.;[Xue, W. C.; Zhang, Y. Q.; Wang, C. W.; Liu, J. C.; Tan, W. J.; Zheng, C.] Univ Chinese Acad Sci, Beijing, Peoples R China.;[Yi, Q. B.] Xiangtan Univ, Sch Phys & Optoelect, Xiangtan, Peoples R China.;[Lu, G. P.] Univ Sci & Technol China, Sch Earth & Space Sci, Hefei, Peoples R China.
通讯机构：
[Xiong, SL ] C;Chinese Acad Sci, Inst High Energy Phys, Key Lab Particle Astrophys, Beijing, Peoples R China.
关键词：
GECAM;terrestrial electron beams;terrestrial gamma-ray flashes
摘要：
<jats:title>Abstract</jats:title><jats:p>Gravitational‐wave high‐energy Electromagnetic Counterpart All‐sky Monitor (GECAM) is a space‐borne instrument dedicated to monitoring high‐energy transients, including Terrestrial Gamma‐ray Flashes (TGFs) and Terrestrial Electron Beams (TEBs). We implemented a TGF/TEB search algorithm for GECAM, with which 147 bright TGFs, 2 typical TEBs and 2 special TEB‐like events are identified during an effective observation time of ∼9months. We show that, with gamma‐ray and charged particle detectors, GECAM can effectively identify and distinguish TGFs and TEBs, and measure their temporal and spectral properties in detail. A very high TGF‐lightning association rate of ∼80% is obtained between GECAM and GLD360 in east Asia region.</jats:p>
作者机构：
[Yan, Xin-Shuai; Yang, Ya-Dong; Li, Shao-Ping; Li, Xin-Qiang] Cent China Normal Univ, Inst Particle Phys, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;[Li, Xin-Qiang] Peking Univ, Ctr High Energy Phys, Beijing 100871, Peoples R China.;[Yang, Ya-Dong] Henan Normal Univ, Inst Particle & Nucl Phys, Xinxiang 453007, Peoples R China.
通讯机构：
[Li, X.-Q.] I;Institute of Particle Physics, China
关键词：
2HDM;Dirac neutrinos;effective neutrino number shift;leptogenesis
摘要：
<jats:title>Abstract</jats:title>
<jats:p>The Dirac neutrino masses could be simply generated by a neutrinophilic scalar doublet with a vacuum being dramatically different from the electroweak one. While the case with an eV-scale vacuum has been widely explored previously, we exploit in this work the desert where the scalar vacuum is of <jats:inline-formula>
<jats:tex-math><?CDATA $\mathcal{O}(\mathrm{keV})$?></jats:tex-math>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_47_4_043109_M1.jpg" xlink:type="simple" />
</jats:inline-formula> scale. In this regime, there would be rare hope to probe the keV-vacuum neutrinophilic scalar model via the lepton-flavor-violating processes, which makes it distinguishable from the widely considered eV-scale vacuum. Although such a keV-vacuum scenario is inert in the low-energy flavor physics, we show that the baryogenesis realized via the lightest Dirac neutrino can be a natural candidate in explaining the baryon asymmetry of the Universe. Furthermore, the Dirac neutrinos with a keV-vacuum scalar can generate a shift of the effective neutrino number within the range <jats:inline-formula>
<jats:tex-math><?CDATA $0.097\leqslant \Delta N_{\rm eff}\leqslant 0.112$?></jats:tex-math>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_47_4_043109_M2.jpg" xlink:type="simple" />
</jats:inline-formula>, which can be probed by the future Simons Observatory experiments. In particular, the model with a minimal value <jats:inline-formula>
<jats:tex-math><?CDATA $\Delta N_{\rm eff}=0.097$?></jats:tex-math>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_47_4_043109_M3.jpg" xlink:type="simple" />
</jats:inline-formula> can already be falsified by the future CMB Stage-IV and Large Scale Structure surveys, providing consequently striking exploratory avenues in the cosmological regime for such a keV-vacuum scenario.</jats:p>
作者机构：
[Yan, Xin-Shuai; Lai, LF; Lai, Li-Fen; Yang, Ya-Dong; Li, Xin-Qiang] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Yan, Xin-Shuai; Lai, LF; Lai, Li-Fen; Yang, Ya-Dong; Li, Xin-Qiang] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;[Yang, Ya-Dong] Zhengzhou Univ, Sch Phys & Microelect, Zhengzhou 450001, Henan, Peoples R China.
通讯机构：
[Lai, LF ] C;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.
摘要：
We investigate the potential for discovering new physics through the low-energy scattering processes e−p→e−(μ−)Λc , which could be accessible in the forthcoming ep scattering experiments once adapted to our proposed setups. In the framework of a general low-energy effective Lagrangian, we demonstrate that, compared with the conventional flavor-changing neutral-current weak decays of charmed hadrons and the dilepton productions at high-energy colliders, the low-energy scattering processes can provide more competitive potentials for hunting the underlying new physics. In some specific leptoquark models, we also show that promising event rates can be expected for both the scattering processes, and point out a possible way to distinguish the experimental signals due to the scalar leptoquarks from those of the vector ones.
通讯机构：
[Shao-Lin Xiong] K;Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, China
关键词：
instrumentation: detectors;methods: data analysis
摘要：
Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) is a dedicated mission, launched in December 2020, for gamma-ray transients, including gamma-ray bursts (GRBs) and soft gamma repeater (SGR) bursts in the multimessenger and multiwavelength astronomy era. Since GECAM consists of two independent spacecrafts (or say instruments), and the framework of data analysis for multiple spacecrafts is distinctive from that for only one spacecraft, which is the case for most GRB missions, we developed a dedicated pipeline called Energetic Transients Joint Analysis System for Multi-INstrument (ETJASMIN) for GECAM mission. This pipeline has been naturally extended to incorporate data from other gamma-ray instruments, including the operating missions, such as Insight-HXMT/HE, Fermi/GBM, Swift/BAT, INTEGRAL/SPI-ACS, Konus-Wind, and GRID, as well as the forthcoming missions, such as SVOM/GRM and HEBS. In this paper, we present this pipeline with a focus on the data analysis procedures, methodology, and results in terms of the localization, verification (classification), spectral, and temporal analyses of gamma-ray transients. We show that this pipeline could provide more accurate, reliable, and comprehensive results than that of individual spacecraft, which is beneficial for gamma-ray transients observation.
期刊：
EUROPEAN PHYSICAL JOURNAL C,2022年82(11):1-16 ISSN：1434-6044
通讯作者：
Xin-Qiang Li
作者机构：
[Yan, Xin-Shuai; Yang, Ya-Dong; Li, Shao-Ping; Li, Xin-Qiang] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Yan, Xin-Shuai; Yang, Ya-Dong; Li, Shao-Ping; Li, Xin-Qiang] Cent China Normal Univ, Key Lab Quark & Lepton Phys, MOE, Wuhan 430079, Hubei, Peoples R China.;[Yang, Ya-Dong] Henan Normal Univ, Inst Particle & Nucl Phys, Xinxiang 453007, Henan, Peoples R China.
通讯机构：
[Xin-Qiang Li] I;Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics(MOE), Central China Normal University, Wuhan, China
摘要：
<jats:title>Abstract</jats:title><jats:p>If the leptoquarks proposed to account for the intriguing anomalies observed in the semileptonic <jats:italic>B</jats:italic>-meson decays, <jats:inline-formula><jats:alternatives><jats:tex-math>$$R_{D^{(*)}}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:msub>
<mml:mi>R</mml:mi>
<mml:msup>
<mml:mi>D</mml:mi>
<mml:mrow>
<mml:mo>(</mml:mo>
<mml:mrow />
<mml:mo>∗</mml:mo>
<mml:mo>)</mml:mo>
</mml:mrow>
</mml:msup>
</mml:msub>
</mml:math></jats:alternatives></jats:inline-formula> and <jats:inline-formula><jats:alternatives><jats:tex-math>$$R_{K^{(*)}}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:msub>
<mml:mi>R</mml:mi>
<mml:msup>
<mml:mi>K</mml:mi>
<mml:mrow>
<mml:mo>(</mml:mo>
<mml:mrow />
<mml:mo>∗</mml:mo>
<mml:mo>)</mml:mo>
</mml:mrow>
</mml:msup>
</mml:msub>
</mml:math></jats:alternatives></jats:inline-formula>, as well as in the anomalous magnetic moment of the muon, <jats:inline-formula><jats:alternatives><jats:tex-math>$$(g-2)_\mu $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:msub>
<mml:mrow>
<mml:mo>(</mml:mo>
<mml:mi>g</mml:mi>
<mml:mo>-</mml:mo>
<mml:mn>2</mml:mn>
<mml:mo>)</mml:mo>
</mml:mrow>
<mml:mi>μ</mml:mi>
</mml:msub>
</mml:math></jats:alternatives></jats:inline-formula>, can be embedded into the scotogenic Dirac neutrino mass models, all these flavor anomalies, together with the origin of neutrino masses and the nature of dark matter, could be potentially addressed in a unified picture. Among the minimal seesaw, one-loop, and two-loop realizations of the dimension-4 effective operator <jats:inline-formula><jats:alternatives><jats:tex-math>$${\mathcal {L}}_{4}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:msub>
<mml:mi>L</mml:mi>
<mml:mn>4</mml:mn>
</mml:msub>
</mml:math></jats:alternatives></jats:inline-formula> for the Dirac neutrino masses, we show that plenty of diagrams associated with the two-loop realizations of <jats:inline-formula><jats:alternatives><jats:tex-math>$${\mathcal {L}}_{4}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:msub>
<mml:mi>L</mml:mi>
<mml:mn>4</mml:mn>
</mml:msub>
</mml:math></jats:alternatives></jats:inline-formula> can support the coexistence of leptoquarks and dark matter candidates. After a simple match of these leptoquarks with the ones introduced to accommodate all the flavor anomalies, we establish the scotogenic Dirac neutrino mass models embedded with leptoquarks, which could address all the problems mentioned above.</jats:p>
作者机构：
[Yang, Ya-Dong; Yuan, Xing-Bo; Li, Xin-Qiang; Shen, Meng] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Wang, Dong-Yang] Jiujiang Univ, Dept Phys, Jiujiang 332005, Peoples R China.;[Yang, Ya-Dong] Zhengzhou Univ, Sch Phys & Microelect, Zhengzhou 450001, Henan, Peoples R China.;[Yang, Ya-Dong; Yuan, Xing-Bo; Li, Xin-Qiang; Shen, Meng] Cent China Normal Univ, Key Lab Quark & Lepton Phys, MOE, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Xing-Bo Yuan] I;Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOE), Central China Normal University, Wuhan, Hubei 430079, China
摘要：
Motivated by the recent anomalies in b -> sl(+)l(-) transitions, we explore a minimal Z' scenario, in which the Z' boson has a flavour-changing coupling to charm and top quarks and a flavour-conserving coupling to muons. It is found that such a Z' boson can explain the current b -> sl(+)l(-)anomalies, while satisfying other flavour and collider constraints simultaneously. The Z' boson can be as light as few hundreds GeV. In this case, the t -> c mu(+)mu(-) decay and the tZ' associated production at the LHC could provide sensitive probes of such a Z' boson. As a special feature, the Z' contributions to all rare B- and K-meson processes are controlled by one parameter. This results in interesting correlations among these processes, which could provide further insights into this scenario. In addition, an extended scenario, in which the Z' boson interacts with the SU (2)(L) fermion doublets with analogous couplings as in the minimal scenario, is also investigated. (C) 2022 Published by Elsevier B.V.
通讯机构：
[Shao-Lin Xiong] K;[Yun-Wei Yu] I;Institute of Astrophysics, Central China Normal University , Wuhan 430079, China<&wdkj&>Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences , 19B Yuquan Road, Beijing 100049, China
关键词：
methods: data analysis;stars: magnetars;X-ray: bursts
期刊：
EUROPEAN PHYSICAL JOURNAL C,2022年82(10):1-31 ISSN：1434-6044
通讯作者：
Xin-Qiang Li
作者机构：
[Cai, Fang-Min; Funatsu, Shuichiro; Li, Xin-Qiang] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Cai, Fang-Min; Funatsu, Shuichiro; Li, Xin-Qiang] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;[Yang, Ya-Dong] Zhengzhou Univ, Sch Phys & Microelect, Zhengzhou 450001, Henan, Peoples R China.
通讯机构：
[Xin-Qiang Li] I;Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics(MOE), Central China Normal University, Wuhan, China
摘要：
<jats:title>Abstract</jats:title><jats:p>We update the Standard Model (SM) predictions for the branching ratios of the rare top-quark decays <jats:inline-formula><jats:alternatives><jats:tex-math>$$t \rightarrow cg(g)$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mrow>
<mml:mi>t</mml:mi>
<mml:mo>→</mml:mo>
<mml:mi>c</mml:mi>
<mml:mi>g</mml:mi>
<mml:mo>(</mml:mo>
<mml:mi>g</mml:mi>
<mml:mo>)</mml:mo>
</mml:mrow>
</mml:math></jats:alternatives></jats:inline-formula>, and evaluate the maximum rates that can be reached in the aligned as well as in the four conventional two-Higgs-doublet models (2HDMs) with <jats:inline-formula><jats:alternatives><jats:tex-math>$$\mathcal {Z}_2$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:msub>
<mml:mi>Z</mml:mi>
<mml:mn>2</mml:mn>
</mml:msub>
</mml:math></jats:alternatives></jats:inline-formula> symmetries. Taking into account the relevant constraints on the model parameters resulting from a global fit obtained at the <jats:inline-formula><jats:alternatives><jats:tex-math>$$95.5\%$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mrow>
<mml:mn>95.5</mml:mn>
<mml:mo>%</mml:mo>
</mml:mrow>
</mml:math></jats:alternatives></jats:inline-formula> confidence level, we find that the branching ratios of <jats:inline-formula><jats:alternatives><jats:tex-math>$$t \rightarrow cg$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mrow>
<mml:mi>t</mml:mi>
<mml:mo>→</mml:mo>
<mml:mi>c</mml:mi>
<mml:mi>g</mml:mi>
</mml:mrow>
</mml:math></jats:alternatives></jats:inline-formula> and <jats:inline-formula><jats:alternatives><jats:tex-math>$$t \rightarrow cgg$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mrow>
<mml:mi>t</mml:mi>
<mml:mo>→</mml:mo>
<mml:mi>c</mml:mi>
<mml:mi>g</mml:mi>
<mml:mi>g</mml:mi>
</mml:mrow>
</mml:math></jats:alternatives></jats:inline-formula> decays can reach up to <jats:inline-formula><jats:alternatives><jats:tex-math>$$3.36\times 10^{-9}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mrow>
<mml:mn>3.36</mml:mn>
<mml:mo>×</mml:mo>
<mml:msup>
<mml:mn>10</mml:mn>
<mml:mrow>
<mml:mo>-</mml:mo>
<mml:mn>9</mml:mn>
</mml:mrow>
</mml:msup>
</mml:mrow>
</mml:math></jats:alternatives></jats:inline-formula> and <jats:inline-formula><jats:alternatives><jats:tex-math>$$2.95\times 10^{-9}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mrow>
<mml:mn>2.95</mml:mn>
<mml:mo>×</mml:mo>
<mml:msup>
<mml:mn>10</mml:mn>
<mml:mrow>
<mml:mo>-</mml:mo>
<mml:mn>9</mml:mn>
</mml:mrow>
</mml:msup>
</mml:mrow>
</mml:math></jats:alternatives></jats:inline-formula> respectively, being therefore of the same order, in the aligned 2HDM (A2HDM). This is obviously different from the SM case, where the predicted branching ratio of the three-body decay <jats:inline-formula><jats:alternatives><jats:tex-math>$$t \rightarrow cgg$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mrow>
<mml:mi>t</mml:mi>
<mml:mo>→</mml:mo>
<mml:mi>c</mml:mi>
<mml:mi>g</mml:mi>
<mml:mi>g</mml:mi>
</mml:mrow>
</mml:math></jats:alternatives></jats:inline-formula> is about two orders of magnitude larger than that of the two-body decay <jats:inline-formula><jats:alternatives><jats:tex-math>$$t \rightarrow cg$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mrow>
<mml:mi>t</mml:mi>
<mml:mo>→</mml:mo>
<mml:mi>c</mml:mi>
<mml:mi>g</mml:mi>
</mml:mrow>
</mml:math></jats:alternatives></jats:inline-formula>. On the other hand, compared with the SM predictions, no significant enhancements are observed in the four conventional 2HDMs with <jats:inline-formula><jats:alternatives><jats:tex-math>$$\mathcal {Z}_2$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:msub>
<mml:mi>Z</mml:mi>
<mml:mn>2</mml:mn>
</mml:msub>
</mml:math></jats:alternatives></jats:inline-formula> symmetries for the branching ratios of these two decays. Nevertheless, the predicted branching ratios of <jats:inline-formula><jats:alternatives><jats:tex-math>$$t \rightarrow cg$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mrow>
<mml:mi>t</mml:mi>
<mml:mo>→</mml:mo>
<mml:mi>c</mml:mi>
<mml:mi>g</mml:mi>
</mml:mrow>
</mml:math></jats:alternatives></jats:inline-formula> and <jats:inline-formula><jats:alternatives><jats:tex-math>$$t \rightarrow cgg$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mrow>
<mml:mi>t</mml:mi>
<mml:mo>→</mml:mo>
<mml:mi>c</mml:mi>
<mml:mi>g</mml:mi>
<mml:mi>g</mml:mi>
</mml:mrow>
</mml:math></jats:alternatives></jats:inline-formula> decays in the A2HDM are still out of the expected sensitivities of the future high-luminosity Large Hadron Collider and the Future Circular Collider in hadron-hadron mode.</jats:p>
