A New Approach to the Problem of Dynamical Quarks in Numerical Simulations of Lattice QCD

Lattice QCD with an even number of degenerate quark flavours is shown to be a limit of a local bosonic field theory. The action of the bosonic theory is real and bounded from below so that standard simulation algorithms can be expected to apply. The feasibility of such calculations is discussed, but no practical tests have yet been made.Comment: pages 0-15, ps-file 147KB, preprint DESY 93-14

Deciphering the role of Epstein-Barr virus in the pathogenesis of T and NK cell lymphoproliferations

Epstein-Barr virus (EBV) is a highly successful herpesvirus, colonizing more than 90% of the adult human population worldwide, although it is also associated with various malignant diseases. Primary infection is usually clinically silent, and subsequent establishment of latency in the memory B lymphocyte compartment allows persistence of the virus in the infected host for life. EBV is so markedly B-lymphotropic when exposed to human lymphocytes in vitro that the association of EBV with rare but distinct types of T and NK cell lymphoproliferations was quite unexpected. Whilst relatively rare, these EBV-associated T and NK lymphoproliferations can be therapeutically challenging and prognosis for the majority of patients is dismal. In this review, we summarize the current knowledge on the role of EBV in the pathogenesis of these tumours, and the implications for treatment. \ud \u

CP violation in B_s mixing from heavy Higgs exchange

The anomalous dimuon charge asymmetry reported by the D0 Collaboration may be due to the tree-level exchange of some spin-0 particles that mediate CP violation in B_s-\bar{B}_s meson mixing. We show that for a range of couplings and masses, the heavy neutral states in a two Higgs doublet model can generate a large charge asymmetry. This range is natural in "uplifted supersymmetry", and may enhance the B^- -> tau nu and B_s -> mu^+ mu^- decay rates. However, we point out that on general grounds the reported central value of the charge asymmetry requires new physics not only in B_s-\bar{B}_s mixing but also in \Delta B = 1 transitions or in B_d-\bar{B}_d mixing.Comment: 5 pages, 1 figure. v2: Equations (17)-(19) included to clarify the flavor structure of uplifted supersymmetr

Laos in 1997: Into ASEAN

Membership in ASEAN will have a long-term effect on the direction of Laos's economic development. Laos has been given until 2008 to meet ASEAN Free Trade Area (AFTA) requirements to reduce tariffs on most goods to below 5%. This should encourage both trade and investment but will force the government to introduce fiscal reforms to make up for the 20% of total revenue it currently derives from tariffs. Laos will also become more fully integrated with its ASEAN neighbors. Overland routes through Laos are seen as essential to increase trade between Thailand and Vietnam and between Thailand and southern China (Yunnan). Bridge and road construction are now priorities, with aid donors and international lending institutions concentrating on infrastructure development. ASEAN membership is already having an impact on Laos's foreign relations. Throughout the year a string of ASEAN heads of state, prime ministers, and foreign ministers visited Vientiane. President Suharto of Indonesia led the way in February, followed by Prime Minister Goh Chok Tong of Singapore in March, Thai Prime Minister Chavalit Youngchaiyudh in June, Vietnamese Prime Minister Vo Van Kiet in August, and President Fidel Ramos of the Philippines in October. Agreements on agriculture, health, narcotics control, and cultural exchange were signed. Singapore has opened an embassy in Vientiane, and Brunei is to follow suit

Admissibility in Statistical Problems Involving a Location or Scale Parameter

The purpose of this short paper is to point out how a slight modification of the formulation of the problem in Brown (1966) yields a variety of admissibility results for problems involving an unknown location or scale parameter. The results sketched, but not proved, include some applications of the analogous two parameter results in Brown and Fox (1974). The applications involve testing problems, estimation problems, and confidence set problems. We treat here only fixed sample size situations; although there also exist similar sequential applications. The proof is essentially that contained in Brown (1966)