Evidence for heavy hyperhydrogen (Λ)(6)h.

Evidence for the neutron-rich hypernucleus (Λ)(6)H is presented from the FINUDA experiment at DAΦNE, Frascati, studying (π+,π-) pairs in coincidence from the K(stop)(-) + (6)Li →(Λ)(6)H + π+ production reaction followed by (Λ)(6)H → (6)He + π- weak decay. The production rate of (Λ)(6) undergoing this two-body π- decay is determined to be (2.9 ± 2.0) × 10(-6)/K(stop)(-). Its binding energy, evaluated jointly from production and decay, is BΛ((Λ)(6)H) = (4.0 ± 1.1) MeV with respect to (5)H+Λ. A systematic difference of (0.98 ± 0.74) MeV between BΛ values derived separately from decay and from production is tentatively assigned to the (Λ)(6)H 0(g.s.)(+) → 1+ excitation.

Experimental observation of optical rotation generated in vacuum by a magnetic field.

We report the experimental observation of a light polarization rotation in vacuum in the presence of a transverse magnetic field. Assuming that data distribution is Gaussian, the average measured rotation is (3.9 +/- 0.5) x 10(-12) rad/pass, at 5 T with 44 000 passes through a 1 m long magnet, with lambda = 1064 nm. The relevance of this result in terms of the existence of a light, neutral, spin-zero particle is discussed.

[Descending necrotizing mediastinitis. Clinical experience and review of the literature]. / La mediastiniti discendenti. Esperienza clinica e revisione della lettertaura.

The occurrence of a Descending Necrotizing Mediastinistis (DNM) usually is a consequence of oropharyngeal infections, which ultimately invade the mediastinum via the cervical fasciae. The clinical course is rapid and often fatal, and is associated with severe systemic symptoms, including fever and hypotension. In these cases, an aggressive surgical approach associated with an appropriate antibiotic treatment is mandatory. Personal experience in the treatment of DNM is presented and a review of the current literature is made; moreover an operative algorhythm is presented.