Highlights

Search for the doubly heavy baryons
${\boldsymbol \varOmega_{\boldsymbol{bc}}^{\bf 0}} $ and$ {\boldsymbol\varXi_{\boldsymbol{bc}}^{\bf 0} }$ decaying to${ \boldsymbol \varLambda_c^+\pi^ }$ and$ {\boldsymbol\varXi_c^+\pi^ }$ 2021, 45(9): 093002. doi: 10.1088/16741137/ac0c70The first search for the doubly heavy$ {{{{\varOmega}_{bc}^{0}}}} $ baryon and a search for the$ {{{{\varXi}_{bc}^{0}}}} $ baryon are performed using$ pp $ collision data collected via the$ {\rm{LHCb}} $ experiment from 2016 to 2018 at a centreofmass energy of$ 13 \;{\rm{TeV}} $ , corresponding to an integrated luminosity of 5.2$ \;{\rm{f}}{{\rm{b}}^{  1}} $ . The baryons are reconstructed via their decays to$ {{{{\varLambda}^+_c}}} {{{{\pi}^}}} $ and$ {{{{\varXi}^+_c}}} {{{{\pi}^}}} $ . No significant excess is found for invariant masses between 6700 and 7300$ \;{\rm{MeV}}/{c^2} $ , in a rapidity range from 2.0 to 4.5 and a transverse momentum range from 2 to 20$ \;{\rm{MeV}}/{c} $ . Upper limits are set on the ratio of the$ {{{{\varOmega}_{bc}^{0}}}} $ and$ {{{{\varXi}_{bc}^{0}}}} $ production crosssection times the branching fraction to$ {{{{\varLambda}^+_c}}}{{{{\pi}^}}} $ ($ {{{{\varXi}^+_c}}}{{{{\pi}^}}} $ ) relative to that of the$ {{{{\varLambda}^0_b}}} $ ($ {{{{\varXi}_{b}^{0}}}} $ ) baryon, for different lifetime hypotheses, at 95% confidence level. The upper limits range from$ 0.5\times10^{4} $ to$ 2.5\times10^{4} $ for the$ {{{{{{{{\varOmega}_{bc}^{0}}}}{{\rightarrow }}{{{{\varLambda}^+_c}}}{{{{\pi}^}}}}}}} $ ($ {{{{{{{{\varXi}_{bc}^{0}}}}{{\rightarrow }}{{{{\varLambda}^+_c}}}{{{{\pi}^}}}}}}} $ ) decay, and from$ 1.4\times10^{3} $ to$ 6.9\times10^{3} $ for the$ {{{{{{{{\varOmega}_{bc}^{0}}}}{{\rightarrow }}{{{{\varXi}^+_c}}}{{{{\pi}^}}}}}}} $ ($ {{{{{{{{\varXi}_{bc}^{0}}}}{{\rightarrow }}{{{{\varXi}^+_c}}}{{{{\pi}^}}}}}}} $ ) decay, depending on the considered mass and lifetime of the$ {{{{\varOmega}_{bc}^{0}}}} $ ($ {{{{\varXi}_{bc}^{0}}}} $ ) baryon. 
Probing topphilic new physics via fourtopquark production
2021, 45(9): 093107. doi: 10.1088/16741137/ac0c6f

Color halo scenario of charmoniumlike hybrids
2021, 45(9): 093111. doi: 10.1088/16741137/ac0ee2The internal structures of
$J^{PC} = 1^{}, (0,1,2)^{+}$ charmoniumlike hybrids are investigated under lattice QCD in the quenched approximation. We define the BetheSalpeter wave function ($ \Phi_n(r) $ ) in the Coulomb gauge as the matrix element of a spatially extended hybridlike operator ($ \bar{c}{c}g $ ) between the vacuum and nth state for each$ J^{PC} $ , with r being the spatial separation between a localized$ \bar{c}c $ component and the chromomagnetic strength tensor. These wave functions exhibit some similarities for states with the aforementioned different quantum numbers, and their rbehaviors (no node for the ground states and one node for the first excited states) imply that r can be a meaningful dynamical variable for these states. Additionally, the mass splittings of the ground states and first excited states of charmoniumlike hybrids in these channels are obtained for the first time to be approximately 1.21.4 GeV. These results do not support the fluxtube description of heavyquarkoniumlike hybrids in the BornOppenheimer approximation. In contrast, a charmoniumlike hybrid can be viewed as a “color halo” charmonium for which a relatively localized color octet$ \bar{c}c $ is surrounded by gluonic degrees of freedom, which can readily decay into a charmonium state along with one or more light hadrons. The color halo picture is compatible with the decay properties of$ Y(4260) $ and suggests LHCb and BelleII to search for$ (0,1,2)^{+} $ charmoniumlike hybrids in$ \chi_{c0,1,2}\eta $ and$ J/\psi \omega (\phi) $ final states.
Just Accepted
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Effect of nonuniform efficiency on higherorder cumulants in heavyion collisions
Published: 20210917, doi: 10.1088/16741137/ac24f6

Scalarpseudoscalar pair production at the Large Hadron Collider at NLO+NLL accuracy in QCD
Published: 20210916, doi: 10.1088/16741137/ac23d2

Twoproton radioactivity of ground and excited states within a unified fission model
Published: 20210916, doi: 10.1088/16741137/ac2425
In Press
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Chromomagnetic and chromoelectric dipole moments of quarks in the reduced 331 model
Published: 20210914, doi: 10.1088/16741137/ac1b9aShow AbstractThe oneloop contributions to the chromomagnetic dipole moment
$\hat\mu_t(q^2)$ and electric dipole moment$\hat d_t(q^2)$ of the top quark are calculated within the reduced 331 model (RM331) for nonzero$q^2$ . It is argued that the results are gauge independent and thus represent valid observable quantities. In the RM331,$\hat \mu_t(q^2)$ receives new contributions from two heavy gauge bosons, namely$Z'$ and$V^\pm$ , and one neutral scalar boson$h_2$ , 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$h_2$ , can provide a nonvanishing$\hat d_t(q^2)$ if there is a$CP$ violating phase. The analytical results are presented in terms of both Feynman parameter integrals and PassarinoVeltman scalar functions, which are useful to crosscheck the numerical results. Both$\hat\mu_t(q^2)$ and$\hat d_t(q^2)$ are numerically evaluated for parameter values still allowed by the constraints from experimental data. It is found that the new oneloop contributions of the RM331 to the real (imaginary) part of$\hat \mu_t(q^2)$ 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$V^\pm$ gauge boson for$\q\$ in the 301000 GeV interval and a mass$m_{V}$ of the order of a few hundreds of GeV. As for$\hat d_t(q^2)$ , it receives its largest contribution from$h_2$ exchange and can reach values of the order of$10^{19}$ , i.e., smaller than the contributions predicted by other standard model extensions. 
Cosmological implications of a B − L charged hidden scalar: leptogenesis and gravitational waves
Published: 20210914, doi: 10.1088/16741137/ac1e09Show AbstractIn this study, we investigated the cosmological implications of a complex singlet scalar
$ {\cal{S}}$ with nontrivial$ BL$ charges in the conformal$ U(1)_{BL}$ theory. It was found that, in a sizable region of parameter space,$ {\cal{S}}$ may disturb the resonant leptogenesis mechanism, which is used to generate baryon asymmetry, and affect the symmetry breaking dynamics in the strong first order phase transition. The stochastic gravitational waves (GWs) produced at the phase transition can be probed in future GW experiments. The GW searches prefer a relatively light$ {\cal{S}}$ at the TeVscale; however, this is difficult to detect directly at future highenergy colliders. 
Description of elastic scattering induced by the unstable nuclei ^{9,10,11,13,14}C
Published: 20210914, doi: 10.1088/16741137/ac1fe1Show AbstractThe elasticscattering angular distributions and total reaction cross sections of
$^{9,10,11,13,14}{\rm{C}}$ projectiles were predicted using the obtained$^{12}{\rm{C}}$ and$^{9}{\rm{Be}}$ global optical model potentials, respectively. The predictions were analyzed in detail by comparison with the available experimental data. The results indicate that the$^{12}{\rm{C}}$ and$^{9}{\rm{Be}}$ global optical model potentials provide a satisfactory description of the elastic scattering data for the reactions induced by the$^{9,10,11,13}{\rm{C}}$ . For the neutronrich carbon isotope$^{14}{\rm{C}}$ , the elastic scattering can be well described by changing the real part radius parameter of the$^{12}{\rm{C}}$ global optical model potential. Possible physical explanations for the observed differences are further discussed.
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