Study on failure mechanism and application of double-layer structure floor with large buried depth and high confined water

The first mining of nearly whole rock lower protective layer working face in Pingdingshan coal mining area is used to liberate the Ji group coal resources of its upper threatened by the gas outburst. The mining of the rock layer at a depth of nearly 1000 meters is bound to increase the depth of the floor damage. Once the L5 weak water-rich aquifer in the aquifuge is disturbed, the indirect recharge channel of the cold ash water is formed, which affects the safety and stability of the rock floor. Firstly, the theoretical model of plastic slip line of double-layer structure floor is established, and the analytical solution of maximum failure depth of double-layer floor under three working conditions is derived. Then through the self-designed similar simulation experimental platform of pore water pressure (spring) and stratum effective stress (jack), the deformation form and failure characteristics of stope roof and floor are simulated and analyzed based on digital image correlation technology. Finally, the borehole strain measurement method was used to carry out on-site monitoring of floor fracture development morphology in Ji15-31040 nearly whole rock working face of Pingdingshan No.12 Coal Mine. The results show that the maximum failure depth of Ji15-31040 nearly whole rock working face floor is 16.59 m by using the plastic slip line theory of double-layer structure floor. The similar simulation experiment reveals that the floor failure is concentrated at both ends of the open-off cut and the working face, with obvious lagging failure characteristics. The maximum failure depth is 17.8 m. After the working face advances 159.9 m into full mining, the floor stress gradually recovers. The field measurement results show that the floor rock mass has a compression-shear slip failure at 7.9 m in front of the working face. The floor before and after the working face is pushed through the borehole shows compression-shear and tension-shear failure, respectively. The maximum failure depth of the floor is between 16.5 m and 18 m. The results of field measurement are in good agreement with theoretical calculation and similar simulation test

Lyn mediates FIP1L1-PDGFRA signal pathway facilitating IL-5RA intracellular signal through FIP1L1-PDGFRA/JAK2/Lyn/Akt network complex in CEL

The Fip1-like1 (FIP1L1)–platelet-derived growth factor receptor alpha (PDGFRA) (F/P) oncogene can cause chronic eosinophilic leukemia (CEL), but requires IL-5 cytokine participation. In this study, we investigate the mechanism of F/P in collaboration with IL-5 in CEL. The results showed that Lyn, a key effector in the IL-5-motivated eosinophil production, is extensively activated in F/P-positive CEL cells. Lyn can associate and phosphorylate IL-5 receptor α (IL-5RA) in F/P-positive cells. Moreover, the activation of Lyn and IL-5R kinase were strengthened when the cells were stimulated by IL-5. Lyn inhibition in F/P-positive CEL cells attenuated cellular proliferation, induced apoptosis, and blocked cell migration and major basic protein (MBP) release. We identified the FIP1L1-PDGFRA/JAK2/Lyn/Akt complex in the F/P-expressing cells which can be disrupted by dual inhibition of JAK2 and Lyn, repressing cell proliferation in both EOL-1(F/P-positive human eosinophilic cell line) and imatinib-resistance (IR) cells. Altogether, our data demonstrate that Lyn is a vital downstream kinase activated by F/P converged with IL-5 signals in CEL cells. Lyn activate and expand IL-5RA intracellular signaling through FIP1L1-PDGFRA/JAK2/Lyn/Akt network complex, provoking eosinophils proliferation and exaggerated activation manifested as CEL

Study of the B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} decay

The decay $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ is studied in proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV using data corresponding to an integrated luminosity of 5 $\mathrm{fb}^{-1}$ collected by the LHCb experiment. In the $\Lambda_{c}^+ K^{-}$ system, the $\Xi_{c}(2930)^{0}$ state observed at the BaBar and Belle experiments is resolved into two narrower states, $\Xi_{c}(2923)^{0}$ and $\Xi_{c}(2939)^{0}$, whose masses and widths are measured to be $$m(\Xi_{c}(2923)^{0}) = 2924.5 \pm 0.4 \pm 1.1 \,\mathrm{MeV}, \\ m(\Xi_{c}(2939)^{0}) = 2938.5 \pm 0.9 \pm 2.3 \,\mathrm{MeV}, \\ \Gamma(\Xi_{c}(2923)^{0}) = \phantom{000}4.8 \pm 0.9 \pm 1.5 \,\mathrm{MeV},\\ \Gamma(\Xi_{c}(2939)^{0}) = \phantom{00}11.0 \pm 1.9 \pm 7.5 \,\mathrm{MeV},$$ where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt $\Lambda_{c}^{+} K^{-}$ sample. Evidence of a new $\Xi_{c}(2880)^{0}$ state is found with a local significance of $3.8\,\sigma$, whose mass and width are measured to be $2881.8 \pm 3.1 \pm 8.5\,\mathrm{MeV}$ and $12.4 \pm 5.3 \pm 5.8 \,\mathrm{MeV}$, respectively. In addition, evidence of a new decay mode $\Xi_{c}(2790)^{0} \to \Lambda_{c}^{+} K^{-}$ is found with a significance of $3.7\,\sigma$. The relative branching fraction of $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ with respect to the $B^{-} \to D^{+} D^{-} K^{-}$ decay is measured to be $2.36 \pm 0.11 \pm 0.22 \pm 0.25$, where the first uncertainty is statistical, the second systematic and the third originates from the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb public pages

Measurement of the ratios of branching fractions R(D∗)\mathcal{R}(D^{*}) and R(D0)\mathcal{R}(D^{0})

The ratios of branching fractions $\mathcal{R}(D^{*})\equiv\mathcal{B}(\bar{B}\to D^{*}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(\bar{B}\to D^{*}\mu^{-}\bar{\nu}_{\mu})$ and $\mathcal{R}(D^{0})\equiv\mathcal{B}(B^{-}\to D^{0}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(B^{-}\to D^{0}\mu^{-}\bar{\nu}_{\mu})$ are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0 fb${ }^{-1}$ of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode $\tau^{-}\to\mu^{-}\nu_{\tau}\bar{\nu}_{\mu}$. The measured values are $\mathcal{R}(D^{*})=0.281\pm0.018\pm0.024$ and $\mathcal{R}(D^{0})=0.441\pm0.060\pm0.066$, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is $\rho=-0.43$. Results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb public pages

Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a $Z$ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 $< p_{\textrm{T}} < 100$ GeV and in the pseudorapidity range $2.5 < \eta < 4$. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb$^{-1}$. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages

Measurement of CP asymmetries and branching fraction ratios of B− decays to two charm mesons

The $CP$ asymmetries of seven $B^-$ decays to two charm mesons are measured using data corresponding to an integrated luminosity of $9\text{fb}^{-1}$ of proton-proton collisions collected by the LHCb experiment. Decays involving a $D^{*0}$ or $D^{*-}_s$ meson are analysed by reconstructing only the $D^0$ or $D^-_s$ decay products. This paper presents the first measurement of $\mathcal{A}^{CP}(B^- \rightarrow D^{*-}_s D^0)$ and $\mathcal{A}^{CP}(B^- \rightarrow D^{-}_s D^{*0})$, and the most precise measurement of the other five $CP$ asymmetries. There is no evidence of $CP$ violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured.The CP asymmetries of seven B$^{−}$ decays to two charm mesons are measured using data corresponding to an integrated luminosity of 9 fb$^{−1}$ of proton-proton collisions collected by the LHCb experiment. Decays involving a D$^{*0}$ or ${D}_s^{\ast -}$ meson are analysed by reconstructing only the D$^{0}$ or ${D}_s^{-}$ decay products. This paper presents the first measurement of $\mathcal{A} ^{CP}$(B$^{−}$→${D}_s^{\ast -}$D$^{0}$) and $\mathcal{A} ^{CP}$(B$^{−}$→${D}_s^{-}$D$^{∗0}$), and the most precise measurement of the other five CP asymmetries. There is no evidence of CP violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured.[graphic not available: see fulltext]The $CP$ asymmetries of seven $B^-$ decays to two charm mesons are measured using data corresponding to an integrated luminosity of $9\text{ fb}^{-1}$ of proton-proton collisions collected by the LHCb experiment. Decays involving a $D^{*0}$ or $D^{*-}_s$ meson are analysed by reconstructing only the $D^0$ or $D^-_s$ decay products. This paper presents the first measurement of $\mathcal{A}^{CP}(B^- \rightarrow D^{*-}_s D^0)$ and $\mathcal{A}^{CP}(B^- \rightarrow D^{-}_s D^{*0})$, and the most precise measurement of the other five $CP$ asymmetries. There is no evidence of $CP$ violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured

Search for the doubly charmed baryon Ω cc +

Abstract: A search for the doubly charmed baryon Ωcc+ with the decay mode Ωcc+ → Ξc+K−π+ is performed using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the LHCb experiment from 2016 to 2018, corresponding to an integrated luminosity of 5.4 fb−1. No significant signal is observed within the invariant mass range of 3.6 to 4.0GeV/c2. Upper limits are set on the ratio R of the production cross-section times the total branching fraction of the Ωcc+ → Ξc+K−π+ decay with respect to the Ξcc++→Λc+K−π+π+ decay. Upper limits at 95% credibility level for R in the range 0.005 to 0.11 are obtained for different hypotheses on the Ωcc+ mass and lifetime in the rapidity range from 2.0 to 4.5 and transverse momentum range from 4 to 15 GeV/c

Angular analysis of B0 -> K*0e+e- decays at LHCb

Contents I Theoretical and experimental overview 3 1 The Standard Model 4 1.1 Particles and symmetries................................................................................................ 4 1.2 Electromagnetic interaction......................................................................................... 6 1.3 Strong interaction............................................................................................................ 8 1.4 Electroweak unification................................................................................................... 9 1.4.1 Charged and neutral currents.......................................................................... 11 1.4.2 The Higgs mechanism ...................................................................................... 12 1.4.3 CKM matrix...................................................................................................... 16 1.5 Beyond the Standard Model......................................................................................... 17 2 The B° K*°e+e~ decay 19 2.1 Flavour changing neutral current ................................................................................ 19 2.2 Effective field theory...................................................................................................... 19 2.2.1 Computation of observables............................................................................. 21 2.3 Angular definitions......................................................................................................... 22 2.4 Differential decay rate................................................................................................... 23 2.5 Angular observables......................................................................................................... 25 2.6 Experimental status ...................................................................................................... 28 2.6.1 Differential branching fractions ...................................................................... 28 2.6.2 Angular analyses................................................................................................ 29 2.6.3 Lepton flavour universality tests...................................................................... 29 2.6.4 Global fits............................................................................................................. 31 II The LHCb detector at the LHC 34 3 The LHC 35 4 The LHCb detector 38 4.1 Tracking system................................................................................................................ 40 4.1.1 Dipole magnet...................................................................................................... 40 4.1.2 Vertex locator...................................................................................................... 41 4.1.3 Tracking stations................................................................................................ 42 4.1.4 Track reconstruction......................................................................................... 44 4.1.5 Primary vertex reconstruction.......................................................................... 47 4.2 Particle identification system......................................................................................... 49 4.2.1 Ring imaging Cherenkovdetectors..................................................................... 50 4.2.2 The calorimeter system...................................................................................... 50 4.2.3 Muon system...................................................................................................... 54 4.2.4 Particle identificationmethods............................................................................ 55 4.3 Trigger system ................................................................................................................... 59 4.3.1 Hardware trigger................................................................................................... 60 4.3.2 Software trigger...................................................................................................... 61 III Angular analysis of B° —>K*°e+e~ decays 63 5 Analysis strategy 64 6 Samples 67 6.1 Simulation generation anddata processing................................................................... 67 6.2 Data...................................................................................................................................... 68 6.3 Simulation ............................................................................................................................. 70 6.3.1 Truth matching..................................................................................................... 70 6.4 Trigger selection.................................................................................................................. 71 6.5 Corrections to thesimulation .......................................................................................... 72 6.5.1 Particle identification variables ........................................................................ 72 6.5.2 Trigger cuts alignment........................................................................................ 74 6.5.3 Trigger efficiency corrections.............................................................................. 76 6.5.4 Reconstruction, kinematic and multiplicity corrections ............................. 80 7 Candidates selection 84 7.1 Preselection........................................................................................................................ 84 7.2 Specific backgrounds........................................................................................................ 86 7.2.1 > 4>e+e~ background..................................................................................... 86 7.2.2 B+ —> K+e+e~ background.............................................................................. 86 7.2.3 Charmonium contributions................................................................................. 88 7.2.4 Signal kaon-pion swaps........................................................................................ 91 7.2.5 Semileptonic decays with h —> e misidentification....................................... 92 7.2.6 Partially reconstructed decays........................................................................... 92 7.2.7 Double semileptonic background........................................................................ 93 7.3 Multivariate analysis........................................................................................................ 93 7.3.1 Input features........................................................................................................ 94 7.3.2 Signal and background samples........................................................................ 94 7.3.3 Training and results ........................................................................................... 95 7.3.4 Response uniformity........................................................................................... 96 7.3.5 Threshold optimisation.......................................................................................... 100 7.4 Low efficiency regioncut......................................................................................................104 7.5 Multiple candidates..............................................................................................................105 7.6 Summary of selections....................................................................................................... 105 8 Elements of the angular analysis 107 8.1 Effective acceptance ............................................................................................................107 8.1.1 Parametrisation.......................................................................... 107 8.1.2 Sample choice.......................................................................................................... 109 8.1.3 Effective acceptance function ............................................................................. 109 8.1.4 Validation.................................................................................................................115 8.2 Components modelling......................................................................................................119 8.2.1 Rare mode............................................................................................................... 119 8.2.2 Control mode......................................................................................................... 127 8.3 Angular fit................................... 130 8.3.1 Weighted unbinned maximum likelihood fit......................................................130 8.3.2 Fit strategy............................................................................................................ 131 8.3.3 Weighted fit features............................................................................................ 132 8.4 Pseudoexperiment studies............................................................................................... 138 8.4.1 Component yields.................................................................................................. 138 8.4.2 Signal and background models............................................................................ 138 8.4.3 Sensitivity............................................................................................................... 141 9 Data fits 143 9.1 Control mode validation.................................................................................................. 143 9.1.1 Angular fit............................................................................................................... 143 9.1.2 Control mode systematic uncertainties............................................................ 144 9.1.3 Results and discussions......................................................................................... 149 9.2 Systematic uncertainties...................................................................................................154 9.2.1 Background models............................................................................................... 155 9.2.2 Effective acceptance parametrisation................................................................160 9.2.3 Control mode leakage............................................................................................ 165 9.2.4 Charmonium combinatorial ................................................................................165 9.2.5 B+ —> K+e+e~ veto ............................................................................................ 166 9.2.6 Peaking backgrounds............................................................................................ 167 9.3 Results and discussions......................................................................................................169 10 Conclusion and outlook 174 Appendix 177 A Simulation correction order 177 B Main MVA threshold optimisation configuration 179 B.l Mass fit set-up .................................................................................................................. 179 B. 2 Pseudoexperiment configuration..................................................................................... 179 C Additional details on systematic uncertainties 183 C. l Alternative combinatorial and DSL modelling strategy........................................... 183 C.1.1 Combinatorial and DSL-like backgrounds......................................................... 183 C.1.2 Modified DSL model............................................................................................ 184 C.1.3 Alternative data fit............................................................................................... 187 C.2 Control mode leakage modelling..................................................................................... 188 C.3 Charmonium combinatorial modelling........................................................................... 188 References 19