Weak decays of 4He-Lambda

We measured the lifetime and the mesonic and non-mesonic decay rates of the 4He-Lambda hypernucleus. The hypernuclei were created using a 750 MeV/c momentum K- beam on a liquid 4He target by the reaction 4He(K-,pi-)4He-Lambda. The 4He-Lambda lifetime was directly measured using protons from Lambda p -> n p non-mesonic decay (also referred to as proton-stimulated decay) and was found to have a value of tau = 245 +/- 24 ps. The mesonic decay rates were determined from the observed numbers of pi-'s and pi0's as Gamma_pi-/Gamma_tot = 0.270 +/- 0.024 and Gamma_pi0/Gamma_tot = 0.564 +/- 0.036, respectively, and the values of the proton- and neutron-stimulated decay rates were extracted as Gamma_p/Gamma_tot = 0.169 +/- 0.019 and Gamma_n/Gamma_tot <= 0.032 (95% CL), respectively. The effects of final-state interactions and possible 3-body Lambda N N decay contributions were studied in the context of a simple model of nucleon-stimulated decay. Nucleon-nucleon coincidence events were observed and were used in the determination of the non-mesonic branching fractions. The implications of the results of this analysis were considered for the empirical Delta I = 1/2 rule and the decay rates of the 4H-Lambda hypernucleus.Comment: 15 pages, 11 figures, published in PRC, revised content to match published versio

The Effect of Cocoa Pod Husk and Green Tea Extract on SMAD3 and FGF2 Expressions in Exposed Dental Pulp

Direct pulp capping employing calcium hydroxide has been used to maintain the pulp’s vitality and health and encourage the pulp cells to establish reparative dentin. It has been recommended to use calcium hydroxide as a material of direct pulp capping due to its beneficial properties. However, calcium hydroxide also has several weaknesses. Cocoa pod husks and green tea contain high polyphenols which are useful for their antibacterial, anti-inflammatory, and antioxidant properties. The extracts of cocoa pod husk and green tea combined with calcium hydroxide are expected to increase the effectiveness of calcium hydroxide as a pulp capping material. Objectives to prove the extracts of cocoa pod husk and green tea’s effects on the SMAD3 and FGF2 expressions in mice with perforated dental pulps. A total of 54 rats were used and divided into three groups: given calcium hydroxide treatment with distilled water, calcium hydroxide with the extract of cocoa pod husk, and calcium hydroxide with the extract of green tea. Then, cavities were then restored. The experimental animals from each treatment group were killed on days 3, 7, and 14 to observe their SMAD3 and FGF2 expressions. Data analysis with the Tukey HSD test for SMAD3 and FGF2 expressions on the two test groups suggested no significant difference. The extracts of cocoa pod husk and green tea have the same ability to increase the SMAD3 and FGF2 expression in exposed dental pulp

Weak decays of Λ⁴He

We measured the lifetime and the mesonic and nonmesonic decay rates of the Λ4He hypernucleus. The hypernuclei were created using a 750 MeV/c momentum K- beam on a liquid 4He target by the reaction 4He (K-,π-)Λ4He. The Λ4He lifetime was directly measured using protons from Λp→np nonmesonic decay (also referred to as proton-stimulated decay) and was found to have a value of τ=245±24 ps. The mesonic decay rates were determined from the observed numbers of π-'s and π○'s as Γπ-/Γtot=0.270±0.024 and Γπ○/Γtot=0.564±0.036, respectively, and the values of the proton- and neutron-stimulated decay rates were extracted as Γp/Γtot=0.169±0.019 and Γn/Γtot⩽0.032 (95% CL), respectively. The effects of final-state interactions and possible three-body ΛNN decay contributions were studied in the context of a simple model of nucleon-stimulated decay. Nucleon-nucleon coincidence events were observed and were used in the determination of the nonmesonic branching fractions. The implications of the results of this analysis were considered for the empirical ΔI=1/2 rule and the decay rates of the Λ4H hypernucleus.</p