DETECTOR DEVELOPMENT FOR SUPERB
The SuperB experiment is a proposed high luminosity flavour physics experiment that will perform detailed studies of the decays of B, D, Y mesons and tau leptons with billions of events. Using these events it will be possible to start reconstructing the Lagrangian for any physics beyond the Standard Model that may be encountered, and precise tests of the Standard Model of particle physics. More information on the SuperB experiment can be found at the following:
- SuperB Public Web Page
- SuperB Collaboration Web Page
- There are progress reports available for the detector, and physics.
Current research and development activities involve simulation studies of the performance of an all pixel detector concept, prototyping support structures for this detector, and we are starting to test prototype pixel sensors that are variants of a proposed SuperB pixel detector.
Pixel Detector Concept
With colleagues at Rutherford Appleton Laboratory we are working on an all pixel vertex detector concept for SuperB. This detector would contain 5-6 layers of INMAPS pixel sensors arranged either in a long-barrel or lampshade geometry. The global geometry of this detector is being studied using SuperB Fast and Full simulations, and prototypes of INMAPS sensors similar to those intended for use on SuperB are being tested in our clean room.
(left) The long barrel all pixel vertex detector concept, and (right) a stave, showing several sensors on a CFRP support, with cooling channels illustrated (images taken from arXiv:1008.1938).
Support Structure prototyping
A proposed support structure for the outer layers of the SuperB pixel detector involves the construction of long thin "staves" of carbon fibre (CFRP). The structural body of such a stave is similar to R&D being developed for the ATLAS SCT upgrade programme here at QMUL. An early prototype of the ATLAS stave with a corrugated core material is shown below.
While the material budet restrictions and cooling requirements of ATLAS and SuperB differ significantly, these developments for the ATLAS upgrade programme are equally valid tests of a SuperB stave.
We are actively working on low level tracking studies to understand the performance of the SuperB silicon vertex tracker baseline, and proposed all pixel detector variants. In addition to investigating the detector response to single particles, we are actively working on a number of physics channels to investigate how the end performance on important observables may be affected by a given choice of detector geometry. Among other things, we are studing
- The lepton flavour violating mode tau->3mu. The aim of studying ths mode is to understand basic tracking performance, and investigate how the missing energy on the tag side tau is affected by choice of vertex detector.
- The charmless hadronic decays B0->pi+pi- and B0->pi0pi0, related to the Unitarity Triangle angle alpha. By studying these channels we aim to understand basic tracking performance, time-dependent CP asymmetry detector resolution, and the affect of vertex detector material on neutral final states.
- B->D*pi decays, where we are interested in understanding the slow pion efficiency as this is an important aspect to many time-dependent and mixing observables that SuperB will measure.
In addition to the academics working on this project, there have been a number of summer interns who have contributed to physics studies investigating detector optimisation for SuperB. These include:
- Cedric Weiland (ENS Lyon) tau->3mu
- Samuel Coquereau (Orsay) tau->3mu
- Tejpal Rupra (QMUL) tracking
- Ryan Forster (Surrey) B->pi+pi-
- Daniel O'Hanlon (Exeter) The effect of magnetic field on D meson reconstruction at the Y(4S) and psi(3770)
The QMUL SuperB group have participated in the following publications:
- SuperB Progress Reports: Detector
- SuperB Progress Reports: Physics.
- Design Study for a SuperB Pixel Vertex Detector.
Please contact Dr. A. J. Bevan for more information.