1,228 research outputs found
A novel experiment searching for the lepton flavour violating decay mu -> eee
Since the discovery of neutrino oscillations it is known that lepton flavour
is not conserved. Lepton flavour violating processes in the charged lepton
sector have so far however eluded detection; as they are heavily suppressed in
the standard model of particle physics, an observation would be a clear signal
for new physics and help to understand the source of neutrino masses and CP
violation. We propose a novel experiment searching for the decay mu -> eee with
the aim of ultimately reaching a sensitivity of 10^-16, an improvement by four
orders of magnitude compared to previous experiments. The technologies enabling
this step are thin high-voltage monolithic active pixel sensors for precise
tracking at high rates with a minimum of material and scintillating fibres for
high resolution time measurements.Comment: 4 pages, 3 figures, contribution to NUFACT 11, XIIIth International
Workshop on Neutrino Factories, Super beams and Beta beams, 1-6 August 2011,
CERN and University of Genev
Multi-Gigabit Wireless data transfer at 60 GHz
In this paper we describe the status of the first prototype of the 60 GHz
wireless Multi-gigabit data transfer topology currently under development at
University of Heidelberg using IBM 130 nm SiGe HBT BiCMOS technology. The 60
GHz band is very suitable for high data rate and short distance applications as
for example needed in the HEP experments. The wireless transceiver consist of a
transmitter and a receiver. The transmitter includes an On-Off Keying (OOK)
modulator, an Local Oscillator (LO), a Power Amplifier (PA) and a BandPass
Filter (BPF). The receiver part is composed of a BandPass- Filter (BPF), a Low
Noise Amplifier (LNA), a double balanced down-convert Gilbert mixer, a Local
Oscillator (LO), then a BPF to remove the mixer introduced noise, an
Intermediate Amplifier (IF), an On-Off Keying demodulator and a limiting
amplifier. The first prototype would be able to handle a data-rate of about 3.5
Gbps over a link distance of 1 m. The first simulations of the LNA show that a
Noise Figure (NF) of 5 dB, a power gain of 21 dB at 60 GHz with a 3 dB
bandwidth of more than 20 GHz with a power consumption 11 mW are achieved.
Simulations of the PA show an output referred compression point P1dB of 19.7 dB
at 60 GHz.Comment: Proceedings of the WIT201
Minilaparotomy a Good Option in Specific Cases: A Case Report of Bilateral Ovarian Germ Cell Tumor
Mature cystic teratomas (MCTs) of the ovary represent 44% of ovarian neoplasmas. The surgical approach is important in young women especially for the cosmetic results. Nowadays most of the ovarian surgeries can be performed laparoscopically. An alternative between laparoscopy and laparotomy is the minilaparotomy (ML) which can be an interesting option, thanks to the small incision. We report a 39-year-old woman who was referred to our hospital with acute abdominal pain. In her past history the patient had an uncomplicated delivery. During pregnancy a 6âcm bilateral MCT was diagnosed and expectant management was followed. A left-sided ovarial torsion was postulated, and laparoscopic detorsion was performed. To avoid a rupture of the left MCT, the operation was interrupted. To remove the cyst, a ML was done two weeks later. A left-sided salpingo-oophorectomy was performed due to a large cyst including the entire ovary. On the other side, the right dermoid cyst was entirely removed. The advantage of a ML is not only shorter operating time with less learning curve compared to laparoscopy but also the possibility to extract the adnexal mass from the abdominal cavity with lower risk of rupture and in addition the possibility to preserve more ovarian tissue
Irradiation study of a fully monolithic HV-CMOS pixel sensor design in AMS 180 nm
High-Voltage Monolithic Active Pixel Sensors (HV-MAPS) based on the 180 nm
HV-CMOS process have been proposed to realize thin, fast and highly integrated
pixel sensors. The MuPix7 prototype, fabricated in the commercial AMS H18
process, features a fully integrated on-chip readout, i.e. hit-digitization,
zero suppression and data serialization. It is the first fully monolithic
HV-CMOS pixel sensor that has been tested for the use in high irradiation
environments like HL-LHC. We present results from laboratory and test beam
measurements of MuPix7 prototypes irradiated with neutrons (up to
) and protons (up to ) and compare the performance with non-irradiated
sensors. Efficiencies well above 90 % at noise rates below 200 Hz per pixel are
measured. A time resolution better than 22 ns is measured for all tested
settings and sensors, even at the highest irradiation fluences. The data
transmission at 1.25 Gbit/s and the on-chip PLL remain fully functional
P-Selectivity, Immunity, and the Power of One Bit
We prove that P-sel, the class of all P-selective sets, is EXP-immune, but is
not EXP/1-immune. That is, we prove that some infinite P-selective set has no
infinite EXP-time subset, but we also prove that every infinite P-selective set
has some infinite subset in EXP/1. Informally put, the immunity of P-sel is so
fragile that it is pierced by a single bit of information.
The above claims follow from broader results that we obtain about the
immunity of the P-selective sets. In particular, we prove that for every
recursive function f, P-sel is DTIME(f)-immune. Yet we also prove that P-sel is
not \Pi_2^p/1-immune
Faster transport with a directed quantum walk
We give the first example of faster transport with a quantum walk on an
inherently directed graph, on the directed line with a variable number of
self-loops at each vertex. These self-loops can be thought of as adding a
number of small dimensions. This is a discrete time quantum walk using the
Fourier transform coin, where the walk proceeds a distance in
constant time compared to classically, independent of the number
of these small dimensions. The analysis proceeds by reducing this walk to a
walk with a two dimensional coin.Comment: 3 pages, 2 figures. To be published in Phys. Rev. A. v2: Minor
wording changes. For Mathematica simulation source, see
http://panic.berkeley.edu/~shoyer
The MuPix Telescope: A Thin, high Rate Tracking Telescope
The MuPix Telescope is a particle tracking telescope, optimized for tracking
low momentum particles and high rates. It is based on the novel High-Voltage
Monolithic Active Pixel Sensors (HV-MAPS), designed for the Mu3e tracking
detector. The telescope represents a first application of the HV-MAPS
technology and also serves as test bed of the Mu3e readout chain. The telescope
consists of up to eight layers of the newest prototypes, the MuPix7 sensors,
which send data self-triggered via fast serial links to FPGAs, where the data
is time-ordered and sent to the PC. A particle hit rate of 1 MHz per layer
could be processed. Online tracking is performed with a subset of the incoming
data. The general concept of the telescope, chip architecture, readout concept
and online reconstruction are described. The performance of the sensor and of
the telescope during test beam measurements are presented.Comment: Proceedings TWEPP 2016, 8 pages, 7 figure
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