67 research outputs found
Two-Photon Effects in Lepton-AntiLepton Pair Photoproduction from a Nucleon Target using Real Photons
We consider the production of a lepton-antilepton pair by real photons off a
hadronic target. The interference of one and two photon exchange amplitudes
leads to a charge asymmetry term that may be calculated explicitly in the
large-t limit in terms of hadronic distribution amplitudes. A rather compact
expression emerges for the leading order asymmetry at fixed angle in the
centre-of-mass of the lepton pair. The magnitude appears sizeable and is
approximately independent of the pair mass in the asymptotic limit.Comment: 14 pages, 7 figures. Title changed, references adde
Pakistan’s Higher Education System—What went Wrong and How to Fix it.
None of Pakistan’s 50+ public universities comes even close to
being a university in the real sense of the word. Compared to
universities in India and Iran, the quality of both teaching and
research is far poorer. Most university “teaching” amounts to a mere
dictation of notes which the teacher had copied down when he was a
student in the same department, examinations are tests of memory,
student indiscipline is rampant, and a large number of teachers commit
academic fraud without ever getting punished. In some universities the
actual number of teaching days in a year adds up to less than half the
officially required number. Some campuses are run by gangs of hoodlums
and harbour known criminals, while others have had Rangers with machine
guns on continuous patrol for years on end. Common wisdom has always
been that increased funding can solve all, or at least most, of the
systemic problems that bedevil higher education in Pakistan. But
Pakistan offers an instructive counterexample: a many-fold increase in
university funding from 2002-2008 resulted in, at best, only marginal
improvements in a few parts of the higher education sector. This
violation of “commonsense” points to the need for some fresh thinking.
The analysis of Pakistan’s higher education system divides naturally
into three parts: consideration of the necessary background;
understanding the meaning of university quality in the Pakistani
context; and exploring the space of solutions
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