Resummation prediction on gauge boson pair production with a jet veto

We investigate the resummation effects with a jet veto, for WZ and ZZ productions at the LHC in soft-collinear effective theory. We present the invariant mass distributions and the total cross section with different jet veto and jet radius for these process at Next-to-Next-to-Leading-Logarithmic level. Our results show that the jet-veto resummation can increase the jet-veto cross section and decrease the scale uncertainties, especially in the large center-of-mass energy. We find that for pt_veto>30 GeV and R=0.4, the resummation results can increase POWHEG+PYTHIA predictions by about 19% for WZ production and 18% for ZZ production, respectively. Our results agree with the CMS data for WZ productions within 2$\sigma$ C.L. at 8 TeV, which can explain the 2$\sigma$ discrepancy between the CMS experimental results and theoretical predictions based on NLO calculation with parton showers.Comment: 15 pages, 11 figure

Resummation prediction on the jet mass spectrum in one-jet inclusive production at the LHC

We study the factorization and resummation prediction on the jet mass spectrum in one-jet inclusive production at the LHC based on soft-collinear effective theory. The soft function with anti-$k_T$ algorithm is calculated at next-to-leading order and its validity is demonstrated by checking the agreement between the expanded leading singular terms with the exact fixed-order result. The large logarithms $\ln^{n} (m_J^2/p_T^2)$ and the global logarithms $\ln^{n} (s_4/p_T^2)$ in the process are resummed to all order at next-to-leading logarithmic and next-to-next-to-leading logarithmic level, respectively. The cross section is enhanced by about 23% from the next-to-leading logarithmic level to next-to-next-to-leading logarithmic level. Comparing our resummation predictions with those from Monte Carlo tool PYTHIA and ATLAS data at the 7 TeV LHC, we find that the peak positions of the jet mass spectra agree with those from PYTHIA at parton level, and the predictions of the jet mass spectra with non-perturbative effects are in coincidence with the ATLAS data. We also show the predictions at the future 13 TeV LHC.Comment: 43 pages, 10 figure

Threshold Resummation for WZ and ZZ Pair Production at the LHC

We perform the threshold resummation for WZ and ZZ pair production at the next-to-next-to-leading logarithmic accuracy in Soft-Collinear Effective Theory at the LHC. Our results show that the resummation effects increase the total cross sections by about 7% for ZZ production and 12% for WZ production with$\sqrt{S}= 7,~8,~13 and 14 TeV, respectively, and the scale uncertainties are significantly reduced. Besides, our numerical results are well consistent with experimental data reported by the ATLAS and CMS collaborations.Comment: 14 pages, 8 figures, 2 tables, version published in Phys.Rev.

KS0−KL0K_S^0-K_L^0 Asymmetries and CPCP Violation in Charmed Baryon Decays into Neutral Kaons

We study the $K^0_S-K^0_L$ asymmetries and $CP$ violations in charm-baryon decays with neutral kaons in the final state. The $K^0_S-K^0_L$ asymmetry can be used to search for two-body doubly Cabibbo-suppressed amplitudes of charm-baryon decays, with the one in $\Lambda^+_c\to pK^0_{S,L}$ as a promising observable. Besides, it is studied for a new $CP$-violation effect in these processes, induced by the interference between the Cabibbo-favored and doubly Cabibbo-suppressed amplitudes with the neutral kaon mixing. Once the new CP-violation effect is determined by experiments, the direct $CP$ asymmetry in neutral kaon modes can then be extracted and used to search for new physics. The numerical results based on $SU(3)$ symmetry will be tested by the experiments in the future.Comment: 15 pages, 3 tables. Version published in JHE