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Chiral crossover characterized by Mott transition at finite temperature
Shijun Mao
Published:  
Abstract:
We discuss the proper definition for the chiral crossover at finite temperature, based on the Goldstone's theorem. Different from the usually used maximum change of chiral condensate, we propose to define the crossover temperature by the Mott transition of pseudo-Goldstone bosons, which, by definition, guarantees the Goldstone's theorem. We analytically and numerically demonstrate this property in the frame of a Pauli-Villars regularized NJL model. In external magnetic field, we find that the Mott transition temperature shows an inverse magnetic catalysis effect.
The impact of ATLAS and CMS single differential top-quark pair measurements at ${\sqrt{ s}\bf{=8}}$ TeV on CTEQ-TEA PDFs
Musajan Kadir, Alim Ablat, Sayipjamal Dulat, Tie-Jiun Hou, Ibrahim Sitiwaldi
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By applying the Error PDF Updating Method, we analyze the impact of the absolute and normalized single differential cross-sections for top-quark pair production data from the ATLAS and CMS experiments at the Large Hadron Collider, at a centre-of-mass energy of \begin{document}$ \sqrt{s} = 8 $\end{document} TeV, on the CT14HERA2 PDFs. We find that the top quark pair single differential distributions provide minor constraints on the CT14HERA2 gluon PDF when the nominal CT14HERA2 inclusive jet production data are included in the fit. Larger constraints on the gluon distribution are present when the jet data are removed (CT14HERA2mJ) and/or when increased weights are given to the top data in the CT14HERA2 fits. The weighted \begin{document}$ t\bar t $\end{document} data provide significant constraints on the CT14HERA2mJ gluon PDF, that are comparable to those obtained from inclusive jet production data. Furthermore, we examine the top quark mass sensitivity of the top-quark pair single differential distributions.
Kinetic Energy Distribution for Neutron-Induced Fission of Neptunium Isotopes
P Mehdipour Kaldiani
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The mean total kinetic energy as a function of fission fragments, <TKE> distribution, was presented for neutron-induced fission of \begin{document}$ ^{235-239}$\end{document}Np using the scission point model. The calculated results of <TKE> for neutron-induced fission of \begin{document}$ ^{237,238}$\end{document}Np were calculated and compared with the available experimental data to obtain the deformation parameters in the scission point model. The deformation parameters of fission fragments were discussed at the scission point. Also, the calculated results were compared with the other method's results and experimental data. Then the behavior of <TKE> distribution are studied for the neutron-induced fission of actinides. This indicates that the <TKE> values for neutron-induced fission of actinides with odd mass numbers are greater than these values for neutron-induced fission of actinides with even mass numbers.
A new observable for measuring CP property of top-Higgs interaction
Qing-Hong Cao, Ke-Pan Xie, Hao Zhang, Rui Zhang
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We propose a new dihedral angle observable to measure the CP property of the interaction of top quark and Higgs boson in the \begin{document}$t\bar{t}H$\end{document} production at the 14 TeV LHC. We consider two decay modes of the Higgs boson, \begin{document}$H\to b\bar{b}$\end{document} and \begin{document}$H\to \gamma\gamma$\end{document} and show that the dihedral angle distribution is able to distinguish the CP-even and the CP-odd hypothesis at 95% confidence level with an integrated luminosity of \begin{document}$\sim 180~{\rm{fb}}^{-1}$\end{document}.
Strong Coupling Constants of the Doubly Heavy Spin-1/2 Baryons with Light Pseudoscalar Mesons
S. Rostami, K. Azizi, A. R. Olamaei
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The strong coupling constants of hadronic multiplets are fundamental parameters which carry information of the strong interactions among participating particles. These parameters can help us construct the hadron-hadron strong potential and gain information about the structure of the involved hadrons. Motivated by the recent observation of the doubly charmed \begin{document}$ \Xi_{cc} $\end{document} state by LHCb, we determine the strong coupling constants among the doubly heavy spin-1/2 baryons, \begin{document}$ \Xi^{(\prime)}_{QQ^\prime } $\end{document}, \begin{document}$ \Omega^{(\prime)}_{QQ^\prime} $\end{document} and light pseudoscalar mesons, \begin{document}$ \pi $\end{document}, K, \begin{document}$ \eta $\end{document} and \begin{document}$ \eta^\prime $\end{document} within the framework of the light cone QCD sum rules. The obtained results may help experimental groups in analysis of the related data at hadron colliders.
Higgs decay to light (pseudo)scalars in the semi-constrained NMSSM
Shiquan Ma, Kun Wang, Jingya Zhu
Published:   , doi: 10.1088/1674-1137
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The next-to minimal supersymmetric standard model (NMSSM) with non-universal Higgs masses, or the semi-constrained NMSSM (scNMSSM), extend the minimal supersymmetric standard model (MSSM) by a singlet superfield and assume universal conditions except for the Higgs sector. It can not only keep the simpleness and grace of the fully constrained MSSM and NMSSM, and relax the tension that they face after the 125-GeV Higgs boson discovered, but also allow for an exotic phenomenon that Higgs decay to a pair of light (\begin{document}$10\sim 60\;{\rm{GeV}}$\end{document}) singlet-dominated (pseudo)scalars (hereafter in this paper we use `scalar' for both scalars and pseudoscalars, considering pseudoscalars can also be called CP-odd scalars). This condition can be classified into three scenarios according to the identities of the SM-like Higgs and the light scalar: (i) the light scalar is CP-odd, and the SM-like Higgs is \begin{document}$h_2$\end{document}; (ii) the light scalar is CP-odd, and the SM-like Higgs is \begin{document}$h_1$\end{document}; (iii) the light scalar is CP-even, and the SM-like Higgs is \begin{document}$h_2$\end{document}. In this work, we compare the three scenarios, checking the interesting parameter regions that lead to the scenarios, the mixing levels of the doublets and singlets, the tri-scalar coupling between the SM-like Higgs and a pair of light scalars, the branching ratio of Higgs decay to the light scalars, and sensitivities in hunting for the exotic decay at the HL-LHC and the future lepton colliders such as CEPC, FCC-ee, and ILC. Finally, several interesting conclusions were drawn, which are useful for understanding the different delicate mechanisms of the exotic decay, and designing colliders in the future.
A Private SUSY 4HDM with FCNC in the Up-sector
M. A. Arroyo-Ureña, J. Lorenzo Díaz-Cruz, Bryan O. Larios-López, M. A. Pérez de León
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We present a SUSY model with four Higgs doublets of the “private type”, where each fermion type (up, down, and charged leptons) obtain their masses from a different Higgs doublet \begin{document}$H_f\,( f = u_1, d, e)$\end{document}. The conditions for anomaly cancellation, imply that the remaining Higgs doublet of the model (\begin{document}$H_{u_2}$\end{document}), must have the same hypercharge as \begin{document}$H_{u_1}$\end{document}, and thus can only couple to up-type quarks, which opens the possibility to have FCNC's only in this sector. We study the Lagrangian of the model, and in particular the Higgs potential, in order to identify the Higgs mass-eigenstates and their interactions; for the Yukawa matrices we consider the 4-texture case. We obtain constraints on the model parameters by using LHC measurements on the properties of the 125 GeV Higgs boson (h), and identify viable regions of parameter space. These constraints are then used to evaluate the prospects to detect the FCNC decay mode \begin{document}$t \to ch$\end{document} at the future high-luminosity (HL) option for the LHC, which are compared with current limits from LHC-run2. Then, we also evaluate the FCNC decay of the next heavier Higgs boson \begin{document}$H_2\to tc$\end{document}, which can reach typically \begin{document}$BR(H_2 \rightarrow tc) \approx {\cal{O}}(10^{-4}-10^{-5} )$\end{document}; the search for the signal at HL-LHC is also studied, finding that it could be detectable for some specific regions of the model parameter space.
The X0(2900) and its heavy quark spin partners in molecular picture
Mei-Wei Hu, Xue-Yi Lao, Pan Ling, Qian Wang
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The \begin{document}$X_0(2900)$\end{document} observed by the LHCb Collaboration recently in the \begin{document}$D^-K^+$\end{document} invariant mass of the \begin{document}$B^+\to D^+D^-K^+$\end{document} process is the first exotic candidate with four different flavors, which opens a new era for the hadron community. Under the assumption that the \begin{document}$X_0(2900)$\end{document} is a \begin{document}$I(J^P)=0(0^+)$\end{document} \begin{document}$\bar{D}^*K^*$\end{document} hadronic molecule, we extract the whole heavy-quark symmetry multiplet formed by the \begin{document}$\left(\bar{D},\bar{D}^*\right)$\end{document} doublet and the \begin{document}$K^*$\end{document} meson. For the bound state case, there would be two additional \begin{document}$I(J^P)=0(1^+)$\end{document} hadronic molecules associated with the \begin{document}$\bar{D}K^*$\end{document} and \begin{document}$\bar{D}^*K^*$\end{document} channels as well as one additional \begin{document}$I(J^P)=0(2^+)$\end{document} \begin{document}$\bar{D}^*K^*$\end{document} molecule. In the light quark limit, they are \begin{document}$36.66~{\rm{MeV}}$\end{document} and \begin{document}$34.22~{\rm{MeV}}$\end{document} below the \begin{document}$\bar{D}K^*$\end{document} and \begin{document}$\bar{D}^*K^*$\end{document} thresholds, respectively, which are unambiguously fixed by the mass position of the \begin{document}$X_0(2900)$\end{document}. For the virtual state case, there would be one additional \begin{document}$I(J^P)=0(1^+)$\end{document} hadronic molecule strongly coupling to the \begin{document}$\bar{D}K^*$\end{document} channel and one additional \begin{document}$I(J^P)=0(2^+)$\end{document} \begin{document}$\bar{D}^*K^*$\end{document} molecule. Searching for these heavy quark spin partners will help shed light on the nature of the \begin{document}$X_0(2900)$\end{document}.
Study of BESIII Trigger Efficiencies with the 2018 J/ψ Data
M. Ablikim, M. N. Achasov, P. Adlarson, S. Ahmed, M. Albrecht, R. Aliberti, A. Amoroso, M. R. An, Q. An, X. H. Bai, Y. Bai, O. Bakina, R. Baldini Ferroli, I. Balossino, Y. Ban, K. Begzsuren, N. Berger, M. Bertani, D. Bettoni, F. Bianchi, J. Bloms, A. Bortone, I. Boyko, R. A. Briere, H. Cai, X. Cai, A. Calcaterra, G. F. Cao, N. Cao, S. A. Cetin, J. F. Chang, W. L. Chang, G. Chelkov, D. Y. Chen, G. Chen, H. S. Chen, M. L. Chen, S. J. Chen, X. R. Chen, Y. B. Chen, Z. J Chen, W. S. Cheng, G. Cibinetto, F. Cossio, X. F. Cui, H. L. Dai, X. C. Dai, A. Dbeyssi, R. E. de Boer, D. Dedovich, Z. Y. Deng, A. Denig, I. Denysenko, M. Destefanis, F. De Mori, Y. Ding, C. Dong, J. Dong, L. Y. Dong, M. Y. Dong, X. Dong, S. X. Du, Y. L. Fan, J. Fang, S. S. Fang, Y. Fang, R. Farinelli, L. Fava, F. Feldbauer, G. Felici, C. Q. Feng, J. H. Feng, M. Fritsch, C. D. Fu, Y. Gao, Y. G. Gao, I. Garzia, P. T. Ge, C. Geng, E. M. Gersabeck, A Gilman, K. Goetzen, L. Gong, W. X. Gong, W. Gradl, M. Greco, L. M. Gu, M. H. Gu, S. Gu, Y. T. Gu, C.
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Abstract:
Using a dedicated data sample taken in 2018 on the J/ψ peak, we perform a detailed study of the trigger efficiencies of the BESIII detector. The efficiencies are determined from three representative physics processes, namely Bhabha-scattering, dimuon production and generic hadronic events with charged particles. The combined efficiency of all active triggers approaches 100% in most cases with uncertainties small enough as not to affect most physics analyses.
Joule-Thomson Expansion of Born-Infeld AdS Black Holes
Shihao Bi, Minghao Du, Jun Tao, Feiyu Yao
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In this paper, the Joule-Thomson expansion of Born-Infeld AdS black holes is studied in the extended phase space, where the cosmological constant is identified with the pressure. The Joule-Thomson coefficient, the inversion curves and the isenthalpic curves are discussed in detail by 4-dimensional black hole. The critical point of Born-Infeld black hole is depicted with varying parameter \begin{document}$ \beta $\end{document} and the charge Q. In \begin{document}$ T-P $\end{document} plane, the inversion temperature curves and isenthalpic curves are obtained with different parameter \begin{document}$ \beta $\end{document} and the charge Q. We find that the missing negative slope is still conserved in Born-Infeld black holes. We also extend our discussion to arbitrary dimension higher than 4. The critical temperature and the minimum of inversion temperature are compared, and the ratio is asymptotically \begin{document}$ 1/2 $\end{document} as Q increases or \begin{document}$ \beta\to\infty $\end{document} in \begin{document}$ D = 4 $\end{document} , and reproduce the previous results in higher dimension.
Thermodynamic extremality relations in the massive gravity
Deyou Chen, Jun Tao, Peng Wang
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A universal relation between the leading correction to the entropy and extremality was gotten in the work of Goon and Penco. In this paper, we extend this work to the massive gravity and investigate thermodynamic extremality relations in a topologically higher-dimensional black hole. A rescaled cosmological constant is added to the action of the massive gravity as a perturbative correction. This correction modifies the extremality bound of the black hole and leads to the shifts of the mass, entropy, etc. Regarding the cosmological constant as a variable related to pressure, we get the thermodynamic extremality relations between the mass and entropy, pressure, charge, parameters ci by accurate calculations, respectively. Finally, these relations are verified by a triple product identity, which shows that the universal relation exists in black holes.
Analysis of Bcτντ at CEPC
Taifan Zheng, Ji Xu, Lu Cao, Dan Yu, Wei Wang, Soeren Prell, Yeuk-Kwan E. Cheung, Manqi Ruan
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The precise determination of the \begin{document}$B_c \to \tau\nu_\tau$\end{document} branching ratio provides an advantageous opportunity for understanding the electroweak structure of the Standard Model, measuring the CKM matrix element \begin{document}$|V_{cb}|$\end{document} and probing new physics models. In this paper, we discuss the potential of measuring the processes of \begin{document}$B_c \to \tau\nu_\tau$\end{document} with \begin{document}$\tau$\end{document} decaying leptonically at the proposed Circular Electron Positron Collider (CEPC). We conclude that during the Z pole operation, the channel signal can achieve five \begin{document}$\sigma$\end{document} significance with \begin{document}$\sim 10^9$\end{document} Z decays, and the signal strength accuracies for \begin{document}$B_c \to \tau\nu_\tau$\end{document} can reach around 1% level at the nominal CEPC Z pole statistics of one trillion Z decays assuming the total \begin{document}$B_c \to \tau \nu_\tau$\end{document} yield is \begin{document}$3.6 \times 10^6$\end{document}. Our theoretical analysis indicates the accuracy could provide a strong constraint on the general effective Hamiltonian for the \begin{document}$b \to c\tau\nu$\end{document} transition. If the total \begin{document}$B_c$\end{document} yield can be determined to \begin{document}${\cal{O}}$\end{document}(1%) level of accuracy in the future, these results also imply \begin{document}$|V_{cb}|$\end{document} could be measured up to \begin{document}${\cal{O}}$\end{document}(1%) level of accuracy.
Effective Field Theory approach to lepto-philic self conjugate dark matter
Hrishabh Bharadwaj, Ashok Goyal
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We study the self conjugate dark matter (DM) particles interacting primarily with the standard model leptons in an effective field theoretical frame work. We consider SM gauge invariant effective contact interactions between the Majorana fermion, real scalar and a real vector DM with leptons by evaluating the Wilson coefficients appropriate for interaction terms upto dimension-8 and obtain constraints on the parameters of the theory from the observed relic density, indirect detection observations and from the DM-electron scattering cross-sections in the direct detection experiments. Low energy LEP data has been used to study sensitivity in the pair production of such low mass \begin{document}$ \leqslant$\end{document} 80 GeV DM particles. Pair production of DM particles of mass \begin{document}$\geqslant$\end{document} 50 GeV in association with mono-photons at the proposed ILC has rich potential to probe such effective operators.
Probing the universality of acceleration scale in the modified Newtonian dynamics with SPARC galaxies
Xin Li, Su-Ping Zhao, Hai-Nan Lin, Yong Zhou
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We probe the universality of acceleration scale \begin{document}$ a_0$\end{document} in Milgrom's modified Newtonian dynamics (MOND) using the recently released rotation curve data from SPARC galaxies. We divide the SPARC data into difference subsamples according to the morphological types of galaxies, and fit the rotation curve data of each subsample with the theoretical prediction of MOND. MOND involves an arbitrary interpolation function which connects the Newtonian region and MOND region. Here we consider five different interpolation functions that are widely discussed in literatures. It is shown that the best-fitting \begin{document}$ a_0$\end{document} significantly depends on the interpolation functions. For a specific interpolation function, \begin{document}$ a_0$\end{document} also depends on the morphological types of galaxies, implying that \begin{document}$ a_0$\end{document} may be not a universal constant. Introducing a dipole correction on \begin{document}$ a_0$\end{document} can significantly improves the fits, and the dipole directions for four in five interpolation functions point towards an approximately consistent direction, but \begin{document}$ a_0$\end{document} still varies for differently interpolation functions.
Minimal Length Effects on Motion of a Particle in Rindler Space
Xiaobo Guo, Kangkai Liang, Benrong Mu, Peng Wang, Mingtao Yang
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Various quantum theories of gravity predict the existence of a minimal measurable length. In this paper, we study effects of the minimal length on the motion of a particle in the Rindler space under a harmonic potential. This toy model captures key features of particle dynamics near a black hole horizon, and allows us to make three observations. First, we find that the chaotic behavior is stronger with the increases of the minimal length effects, which manifests that the maximum Lyapunov characteristic exponents mostly grow, and the KAM curves on Poincaré surfaces of section tend to disintegrate into chaotic layers. Second, in the presence of the minimal length effects, it can take a finite amount of Rindler time for a particle to cross the Rindler horizon, which implies a shorter scrambling time of black holes. Finally, it shows that some Lyapunov characteristic exponents can be greater than the surface gravity of the horizon, violating the recently conjectured universal upper bound. In short, our results reveal that quantum gravity effects may make black holes prone to more chaos and faster scrambling.
Inclusive $ {{\Upsilon(1S,2S,3S)}}$ photoproduction at the CEPC
Xi-Jie Zhan, Jian-Xiong Wang
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The inclusive \begin{document}$ \Upsilon(1S,2S,3S) $\end{document} photoproduction at the future Circular-Electron-Positron-Collider (CEPC) is studied based on the non-relativistic QCD (NRQCD) factorization formalism. Including the contributions from both direct and resolved photons, we present different distributions for \begin{document}$ \Upsilon(1S,2S,3S) $\end{document} production and the results show there will be considerable events, which means that a well measurements on the \begin{document}$ \Upsilon $\end{document} photoprodution could be performed to further study on the heavy quarkonium physics at electron-positron collider in addition to hadron colliders. This supplement study is very important to clarify the current situation of the heavy quarkonium production mechanism.
Slowly rotating Einstein-bumblebee black hole solution and its greybody factor in a Lorentz violation model
Chikun Ding, Xiongwen Chen
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We obtain an exact slowly rotating Einstein-bumblebee black hole solution by solving the corresponding \begin{document}$rr$\end{document} and \begin{document}$t\phi$\end{document} components of the gravitational field equations in both cases: A, \begin{document}$b_\mu=(0,b(r),0,0)$\end{document}; B, \begin{document}$b_\mu= (0,b(r), \mathfrak{b}(\theta),0)$\end{document}. Then we check the other gravitational field equations and the bumblebee field motion equations by using this solution. We find that in the case A, there exists a slowly rotating black hole solution indeed for arbitrary LV (Lorentz violation) coupling constant \begin{document}$\ell$\end{document}; however as in the case B, there exists this slowly rotating solution if and only if the coupling constant \begin{document}$\ell$\end{document} is as small as or smaller than the angular momentum a. Till now there seems to be no full rotating black hole solution, so one can't use the Newman-Janis algorithm to generate a rotating solution in Einstein-bumblebee theory. It is similar as that in Einstein-aether theory where there exists only some slowly rotating black hole solutions. In order to study the effects of this Lorentz symmetry broken, we consider the black hole greybody factor and find that when angular index \begin{document}$l=0$\end{document}, the LV constant \begin{document}$\ell$\end{document} decreases the effective potential and enhances the absorption probability, which is similar to that of the non-minimal derivative coupling theory.
Four α correlations in nuclear fragmentation: a game of resonances
M. Huang, A. Bonasera, S. Zhang, H. Zheng, D. X. Wang, J. C. Wang, N. Song, X. Tang, L. Lu, G. Zhang, Z. Kohley, M. R. D. Rodrigues, Y. G. Ma, S. J. Yennello
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Heavy ion collisions near the Fermi energy produce a ‘freezout’ region where fragments appear and later decay emitting mainly neutrons, protons, alphas and gamma rays. These products carry information on the decaying nuclei in the medium. Fragmentation events might result in high yields of boson particles, especially alpha particles, and carry important information on the nuclear Bose Einstein Condensate (BEC). We study ‘in medium’ 4α correlations and link them to the ‘fission’ of 16O in two 8Be in the ground state or 12C*(Hoyle State)+α. Using novel techniques for the correlation functions we confirm a resonance of 16O at 15.2 MeV excitation energy and the possibility of a lower resonance close to 14.72 MeV. The latter resonance is the result of all α particles having 92 keV relative kinetic energies.
New look at Geiger-Nuttall Law and α clustering of heavy nuclei
Yi-Bin Qian, Zhong-Zhou Ren
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The Geiger-Nuttall (GN) law of α decay is commonly explained in terms of the quantum tunneling phenomenon. In this study, we show that such an explanation is actually not enough regarding the α particle clustering. Such an inference is drawn from the exploration on the involved coefficients of the GN law based on the conventional recognition of α decay, namely the formation of α cluster and its subsequential penetration. The specific roles of the two former processes, played in the GN law, are manifested themselves via the systematical analysis of the calculated and experimental α decay half-lives versus the decay energies across the Z=82 and N=126 shell closures. The α-cluster preformation probability is then found to behave as a GN-like pattern. This previously ignored point is explicitly demonstrated as the product of the interplay between the mean-field and pairing effect, which in turn reveals the structural influence on the formation of α cluster in a simple and clear way. Besides providing an effective way to evaluate the amount of surface α clustering in heavy nuclei, the present conjecture supports other theoretical treatments of the α preformation probability.
Impact of LHCb 13 TeV W and Z pseudo-data on the Parton Distribution Functions
Qilin Deng, Qundong Han, Hang Yin, Sayipjamal Dulat, Tie-Jiun Hou, C.–P. Yuan
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We studied the potential of the LHCb 13 TeV single W± and Z boson pseudo-data on constraining the Parton Distribution Functions (PDFs) of the proton. As an example, we demonstrated the sensitivity of the LHCb 13 TeV data, collected with an integrated luminosity of 5 \begin{document}$ {\rm{fb}}^{-1}$\end{document} and 300 \begin{document}$ {\rm{fb}}^{-1}$\end{document} , respectively, to reducing the PDF uncertainty bands of the CT14HERA2 PDFs, using the error PDF updating package EPUMP. For that, the sensitivities of various experimental observables have been compared. Generally, sizable reductions in PDF uncertainties can be observed in the 300 \begin{document}$ {\rm{fb}}^{-1}$\end{document} data sample, particularly in the small x region. The double differential cross section measurement on Z boson pT and rapidity can greatly reduce the uncertainty bands of u and d quarks in almost all x range, as compared to various single observable measurements.
Shell corrections with finite temperature covariant density functional theory
W. Zhang, W.-L. Lv, T.-T. Sun
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Abstract:
The temperature dependence of the shell corrections to the energy \begin{document}$\delta E_{\rm{shell}}$\end{document}, entropy \begin{document}$T \delta S_{\rm{shell}}$\end{document}, and free energy \begin{document}$\delta F_{\rm{shell}}$\end{document} are studied employing the covariant density functional theory for closed-shell nuclei. Taking \begin{document}$^{144}$\end{document}Sm as an example, studies show that unlike the widely-used exponential dependence \begin{document}$\exp(-E^*/E_d)$\end{document}, the \begin{document}$\delta E_{\rm{shell}}$\end{document} exhibits non-monotonous behavior, i.e., first drops 20% approaching temperature \begin{document}$0.8$\end{document} MeV, and then fades away exponentially. Both the shell corrections to the free energy \begin{document}$\delta F_{\rm{shell}}$\end{document} and to the entropy \begin{document}$T \delta S_{\rm{shell}}$\end{document} can be approximated well using the Bohr-Mottelson forms \begin{document}$\tau/\sinh(\tau)$\end{document} and \begin{document}$[\tau \coth(\tau)-1]/\sinh(\tau)$\end{document} respectively where \begin{document}$\tau\propto T$\end{document}. Further studies for shell corrections in other closed-shell nuclei \begin{document}$^{100}$\end{document}Sn and \begin{document}$^{208}$\end{document}Pb are performed and the same temperature dependencies are obtained.
Measurement of neutron energy spectra of 9Be(d,n)10B reaction with a thick beryllium target
Shuang-Jiao Zhang, Zhi-Jie Hu, Zhi-Ming Hu, Chao Han, Xiao-Hou Bai, Chang-Qi Liu, Chang Huang, Qin Xie, Dong-Ying Huo, Kang Wu, Yang-Bo Nie, Yan-Yan Ding, Kai Zhang, Yu Zhang, Zhi-Yong Deng, Rui Guo, Zheng Wei, Ze-En Yao
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The new measurements of the neutron energy spectra of the 9Be(d,n)10B reaction with a thick beryllium target are carried out by the fast neutron time-of-flight (TOF) spectrometer for the neutron emission angles \begin{document}$\theta=0^\circ$\end{document} and \begin{document}$45^\circ$\end{document}, and the incident deuteron energies are 250 keV and 300 keV, respectively. The neutron contributions from the 9Be(d,n)10B reaction are distributed relatively independently for the ground state of 10B, 1st, 2nd, and 3rd excited state of 10B. The branching ratio of the 9Be(d,n)10B reaction for different excited states of 10B are obtained for the neutron emission angles \begin{document}$\theta=0^\circ$\end{document} and \begin{document}$45^\circ$\end{document}, and the incident deuteron energies are 250 keV and 300 keV, respectively. The branching ratio of the 9Be(d,n)10B reaction for the 3rd excited state is decreasing with increasing of the incident deuteron energy, and the branching ratio for the ground state and 2nd excited state are rising with increasing of the neutron emission angles.
Instability of the regularized 4D charged Einstein-Gauss-Bonnet de-Sitter black hole
Peng Liu, Chao Niu, Cheng-Yong Zhang
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We studied the instability of the regularized 4D charged Einstein-Gauss-Bonnet de-Sitter black holes under charged scalar perturbations. The unstable modes satisfy the superradiant condition, but not all modes satisfying the superradiant condition are unstable. The instability occurs when the cosmological constant is small and the black hole charge is not too large. The Gauss-Bonnet coupling constant makes the unstable black hole more unstable when both the black hole charge and cosmological constant are small, and makes the stable black hole more stable when the black hole charge is large.
Charmed and ϕ meson decay constants from 2+1-flavor lattice QCD
Ying Chen, Wei-Feng Chiu, Ming Gong, Zhaofeng Liu, Yunheng Ma
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On a lattice with 2+1-flavor dynamical domain-wall fermions at the physical pion mass, we calculate the decay constants of \begin{document}$ D_{s}^{(*)} $\end{document}, \begin{document}$ D^{(*)} $\end{document} and \begin{document}$ \phi $\end{document}. The lattice size is \begin{document}$ 48^3\times96 $\end{document}, which corresponds to a spatial extension of \begin{document}$ \sim5.5 $\end{document} fm with the lattice spacing \begin{document}$ a\approx 0.114 $\end{document} fm. For the valence light, strange and charm quarks, we use overlap fermions at several mass points close to their physical values. Our results at the physical point are \begin{document}$ f_D = 213(5) $\end{document} MeV, \begin{document}$ f_{D_s} = 249(7) $\end{document} MeV, \begin{document}$ f_{D^*} = 234(6) $\end{document} MeV, \begin{document}$ f_{D_s^*} = 274(7) $\end{document} MeV, and \begin{document}$ f_\phi = 241(9) $\end{document} MeV. The couplings of \begin{document}$ D^* $\end{document} and \begin{document}$ D_s^* $\end{document} to the tensor current (\begin{document}$ f_V^T $\end{document}) can be derived, respectively, from the ratios \begin{document}$ f_{D^*}^T/f_{D^*} = 0.91(4) $\end{document} and \begin{document}$ f_{D_s^*}^T/f_{D_s^*} = 0.92(4) $\end{document}, which are the first lattice QCD results. We also obtain the ratios \begin{document}$ f_{D^*}/f_D = 1.10(3) $\end{document} and \begin{document}$ f_{D_s^*}/f_{D_s} = 1.10(4) $\end{document}, which reflect the size of heavy quark symmetry breaking in charmed mesons. The ratios \begin{document}$ f_{D_s}/f_{D} = 1.16(3) $\end{document} and \begin{document}$ f_{D_s^*}/f_{D^*} = 1.17(3) $\end{document} can be taken as a measure of SU(3) flavor symmetry breaking.
Dibaryons: Molecular versus Compact Hexaquarks
H. Clement, T. Skorodko
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Hexaquarks constitute a natural extension of complex quark systems like also tetra- and pentaquarks do. To this end the current status of \begin{document}$d^*(2380)$\end{document} in both experiment and theory is reviewed. Recent high-precision measurements in the nucleon-nucleon channel and analyses thereof have established \begin{document}$d^*(2380)$\end{document} as an indisputable resonance in the long-sought dibaryon channel. Important features of this \begin{document}$I(J^P) = 0(3^+)$\end{document} state are its narrow width and its deep binding relative to the \begin{document}$\Delta(1232)\Delta(1232)$\end{document} threshold. Its decay branchings favor theoretical calculations predicting a compact hexaquark nature of this state. We review the current status of experimental and theoretical studies on \begin{document}$d^*(2380)$\end{document} as well as new physics aspects it may bring in the future. In addition, we review the situation at the \begin{document}$\Delta(1232) N$\end{document} and \begin{document}$N^*(1440)N$\end{document} thresholds, where evidence for a number of resonances of presumably molecular nature have been found --- similar to the situation in charmed and beauty sectors. Finally we briefly discuss the situation of dibaryon searches in the flavored quark sectors.
Systematic study of α decay half-lives within the Generalized Liquid Drop Model with various versions of proximity energies
Jun-Gang Deng, Hong-Fei Zhang
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It is universally acknowledged that the Generalized Liquid Drop Model (GLDM) has two advantages that over other α decay theoretical models: introducing the quasimolecular shape mechanism and proximity energy. In the past few decades, the original proximity energy has been improved by numerous works. In the present work, the different improvements of proximity energy are examined when they are applied to GLDM for enhancing the calculation accuracy and prediction ability of α decay half-lives for known and unsynthesized superheavy nuclei. The calculations of α half-lives have systematic improvements in reproducing experimental data after choosing a more suitable proximity energy applied to GLDM. Encouraged by this, the α decay half-lives of even-even superheavy nuclei with Z=112-122 are predicted by the GLDM with a more suitable proximity energy. The predictions are consistent with calculations by the improved Royer formula and the universal decay law. In addition, the features of predicted α decay half-lives imply that the next double magic nucleus after 208Pb is 298Fl.
Analyses of multi-pion Bose-Einstein correlations for granular sources with coherent pion-emission droplets
Ghulam Bary, Wei-Ning Zhang, Peng Ru, Jing Yang
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The ALICE Collaboration measure the three- and four-pion Bose-Einstein correlations (BECs) in Pb-Pb collisions at the Large Hadron Collider (LHC). It is speculated that the significant suppressions of multi-pion BECs are due to a considerable degree of coherent pion emission in the collisions. In this paper, we study the multi-pion BEC functions in a granular source model with coherent pion-emission droplets. We find that the intercepts of multi-pion correlation functions at the relative momenta near zero are sensitive to droplet number in the granular source. They decrease with decreasing droplet number. The three-pion correlation functions for the evolving granular sources with momentum-dependent partially coherent pion-emission droplets are in basic agreement with the experimental data in Pb-Pb collisions at \begin{document}$ \sqrt{s_{NN}}=2.76$\end{document} TeV at the LHC. However, the model results of four-pion correlation function are inconsistent with the experimental data. The investigations of the normalized multi-pion correlation functions of the granular sources indicate that there is an interesting enhancement of the normalized four-pion correlation function in moderate relative-momentum region.
General neutrino mass spectrum and mixing properties in seesaw mechanisms
Wojciech Flieger, Janusz Gluza
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Neutrinos stand out among elementary particles through their unusually small masses. Various seesaw mechanisms attempt to explain this fact. In this work applying insights from matrix theory we are in a position to treat variants of seesaw mechanisms in a general manner. Specifically, using Weyl's inequalities we discuss and rigorously prove under which conditions the seesaw framework leads to a mass spectrum with exactly three light neutrinos. We find an estimate on the mass of heavy neutrinos to be the mass obtained by neglecting light neutrinos shifted at most by the maximal strength of the coupling to the light neutrino sector. We provide analytical conditions allowing to prescribe that precisely two out of five neutrinos are heavy. For higher-dimensional cases the inverse eigenvalue methods are used. In particular, for the CP invariant scenarios we show that if the neutrino sector has a valid mass matrix after neglecting the light ones, i.e. the respective mass submatrix is positive definite, then large masses are provided by matrices with large elements accumulated on the diagonal. Finally, the Davis-Kahan theorem is used to show how masses affect the rotation of light neutrino eigenvectors from the standard Euclidean basis. This general observation concerning neutrino mixing together with results on the mass spectrum properties opens directions for further neutrino physics studies using matrix analysis.
The instability of AdS black holes with lattices
Yi Ling, Meng-He Wu
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The Anti-de Sitter (AdS) black hole with lattice structure plays an essential role in the study of the optical conductivity in holographic approach. We investigate the instability of this sort of black holes which may lead to the holographic description of charge density waves. In the presence of homogeneous axion fields, we show that the instability of AdS-Reissner-Nordström(AdS-RN) black hole is always suppressed. However, in the presence of Q-lattices, we find that the unstable region becomes the smallest in the vicinity of the critical region for metal/insulator phase transition. This novel phenomenon is reminiscent of the behavior of the holographic entanglement entropy during quantum phase transition.
Systematic study of the Woods-Saxon potential parameters between heavy-ions
Lin GAN, Hong-Li ZHI, Hui-Bin SUN, Shi-Peng HU, Er-Tao LI, Jian ZHONG
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Experimental elastic scattering angular distributions of 11B, 12C and 16O + heavy-ions were used to study the Woods-Saxon potential parameters. The diffuseness parameters were found to have best fitted values for each system, and a linear expression of diffuseness parameters with \begin{document}$A_1^{1/3}+A_2^{1/3}$\end{document} was summarized. The correlations of potential depths and radius parameters with \begin{document}$A_1^{1/3}+A_2^{1/3}$\end{document} were revealed with the limitation of diffuseness parameter formula. As the incident energies of most analyzed reactions are below and around the Coulomb barrier, the energy dispersion relation between the real and imaginary potentials was taken into consideration to study the ratio of the imaginary and real potential well depths, and the expression of \begin{document}$W/V$\end{document} was concluded. With the limitation of volume integrals calculated with S\begin{document}$\tilde{a}$\end{document}o Paulo potential, parameterized formulas for depths and radius parameters were obtained. The deduced systematic Woods-Saxon potential parameters in present work can reproduce not only the experimental data of elastic scattering angular distributions induced by 11B, 12C and 16O, but also some elastic scattering induced by other heavy-ions.
J/Ψ-J/Ψ scattering cross sections of Quadratic and Cornell Potentials
M. Imran Jamil, S.M. Sohail Gilani, Ahmad Wasif, Abdul Sattar Khan, Ahmad Awan
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We study the scattering of J/\begin{document}$\Psi$\end{document} - J/\begin{document}$\Psi$\end{document} mesons using quadratic and Cornell potentials in our tetraquark (\begin{document}${\rm{c\bar cc\bar c}}$\end{document}) system. The system’s wavefunction in the restricted gluonic basis is written by utilizing adiabatic approximation and Hamiltonian is used via quark potential model. Resonating group technique is used to get the integral equations which are solved to get the unknown inter-cluster dependence of the total wavefunction of our tetraquark system. T-Matrix elements are calculated from the solutions and eventually the scattering cross sections are obtained using the two potentials respectively. We compare these cross sections and find that the magnitude of scattering cross sections of quadratic potential are higher than Cornell potential.
Solution to the Sudakov suppressed Balitsky-Kovchegov equation and its application to the HERA data
Wenchang Xiang, Mengliang Wang, Yanbing Cai, Daicui Zhou
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We analytically solve the Sudakov suppressed Balitsky-Kovchegov evolution equation with the fixed and running coupling constants in the saturation region. The analytic solution of the S-matrix shows the \begin{document}$\exp(-{\cal{O}}(\eta^2))$\end{document} rapidity dependence of the solution with the fixed coupling constant is replaced by \begin{document}$\exp(-{\cal{O}}(\eta^{3/2}))$\end{document} dependence in the smallest dipole running coupling case rather than obeying the law found in our previous publication, in which all the solutions of the next-to-leading order evolution equations comply with \begin{document}$\exp(-{\cal{O}}(\eta))$\end{document} rapidity dependence once the QCD coupling is switched from the fixed coupling to the smallest dipole running coupling prescription. This finding indicates that the corrections of the sub-leading double logarithms in the Sudakov suppressed evolution equation are significant, which compensate part of the evolution decrease of the dipole amplitude made by running coupling effect. To test the analytic findings, we calculate the numerical solutions of the Sudakov suppressed evolution equation, the numerical results confirm the analytic outcomes. Moreover, we use the numerical solutions of the evolution equation to fit the HERA data. It shows that the Sudakov suppressed evolution equation can give good quality fit to the data.
Medium modifications of girth distributions for inclusive jets and Z0+jet in relativistic heavy-ion collisions at the LHC
Jun Yan, Shi-Yong Chen, Wei Dai, Ben-Wei Zhangy, Enke Wang
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In this paper we investigate the medium modifications of girth distributions for inclusive jets and \begin{document}$Z^0$\end{document} tagged jets with small radius (\begin{document}$R=0.2$\end{document}) in Pb+Pb collisions with \begin{document}$\sqrt{s}=2.76$\end{document} TeV at the LHC. The partonic spectrum in the initial hard scattering of elementary collisions are obtained by a event generator POWHEG+PYTHIA, which matches the next-to-leading (NLO) matrix elements with parton showering, and energy loss of fast parton traversing in hot/dense QCD medium is calculated by Monte Carlo simulation within Higher-Twist formalism of jet quenching in heavy-ion collisions. We present the model calculations of event normalized girth distributions for inclusive jets in p+p and Pb+Pb collisions at \begin{document}$\sqrt{s}=2.76$\end{document} TeV, which give nice descriptions of ALICE measurements. It is shown that the girth distributions of inclusive jets in Pb+Pb are shifted to lower girth region relative to that in p+p. Thus the nuclear modification factor of girth distributions for inclusive jets is larger than unity at small girth region, while smaller than one at large girth region. This behavior results from more soft fragments inside a jet as well as the fraction alteration of gluon/quark initiated jets in heavy-ion collisions. We further predict the girth distributions for \begin{document}$Z^0$\end{document} boson tagged jets in Pb+Pb collisions at \begin{document}$\sqrt{s}=2.76$\end{document} TeV, and demonstrate that the medium modification on girth distributions for \begin{document}$Z^0$\end{document} tagged jets is less pronounced as compared to that for inclusive jets because the dominant components of \begin{document}$Z^0$\end{document} tagged jets are quark-initiated jets.