Laser spectroscopy of muonic deuterium Pohl, Randolf; Nez, François; Fernandes, Luis M. P. ...
Science,
08/2016, Letnik:
353, Številka:
6300
Journal Article
Recenzirano
Odprti dostop
The deuteron is the simplest compound nucleus, composed of one proton and one neutron. Deuteron properties such as the root-mean-square charge radius rd and the polarizability serve as important ...benchmarks for understanding the nuclear forces and structure. Muonic deuterium μd is the exotic atom formed by a deuteron and a negative muon μ⁻. We measured three 2S-2P transitions in μd and obtain rd = 2.12562(78) fm, which is 2.7 times more accurate but 7.5σ smaller than the CODATA-2010 value rd = 2.1424(21) fm. The μd value is also 3.5σ smaller than the rd value from electronic deuterium spectroscopy. The smaller rd, when combined with the electronic isotope shift, yields a "small" proton radius rp, similar to the one from muonic hydrogen, amplifying the proton radius puzzle.
Accurate knowledge of the charge and Zemach radii of the proton is essential, not only for understanding its structure but also as input for tests of bound-state quantum electrodynamics and its ...predictions for the energy levels of hydrogen. These radii may be extracted from the laser spectroscopy of muonic hydrogen (μp, that is, a proton orbited by a muon). We measured the $2{\mathrm{S}}_{1/2}^{\mathrm{F}=0}-2{\mathrm{P}}_{3/2}^{\mathrm{F}=1}$ transition frequency in μp to be 54611.16(1.05) gigahertz (numbers in parentheses indicate one standard deviation of uncertainty) and reevaluated the $2{\mathrm{S}}_{1/2}^{\mathrm{F}=1}-2{\mathrm{P}}_{3/2}^{\mathrm{F}=1}$ transition frequency, yielding 49881.35(65) gigahertz. From the measurements, we determined the Zemach radius, r Z = 1.082(37) femtometers, and the magnetic radius, r M = 0.87(6) femtometer, of the proton. We also extracted the charge radius, r E = 0.84087(39) femtometer, with an order of magnitude more precision than the 2010-CODATA value and at 7σ variance with respect to it, thus reinforcing the proton radius puzzle.
The size of the proton dos Santos, Joaquim M. F; Fernandes, Luis M. P; Liu, Yi-Wei ...
Nature (London),
07/2010, Letnik:
466, Številka:
7303
Journal Article
Recenzirano
The proton is the primary building block of the visible Universe, but many of its properties—such as its charge radius and its anomalous magnetic moment—are not well understood. The root-mean-square ...charge radius, rp, has been determined with an accuracy of 2 per cent (at best) by electron–proton scattering experiments. The present most accurate value of rp (with an uncertainty of 1 per cent) is given by the CODATA compilation of physical constants. This value is based mainly on precision spectroscopy of atomic hydrogen and calculations of bound-state quantum electrodynamics (QED; refs 8, 9). The accuracy of rp as deduced from electron–proton scattering limits the testing of bound-state QED in atomic hydrogen as well as the determination of the Rydberg constant (currently the most accurately measured fundamental physical constant). An attractive means to improve the accuracy in the measurement of rp is provided by muonic hydrogen (a proton orbited by a negative muon); its much smaller Bohr radius compared to ordinary atomic hydrogen causes enhancement of effects related to the finite size of the proton. In particular, the Lamb shift (the energy difference between the 2S1/2 and 2P1/2 states) is affected by as much as 2 per cent. Here we use pulsed laser spectroscopy to measure a muonic Lamb shift of 49,881.88(76) GHz. On the basis of present calculations of fine and hyperfine splittings and QED terms, we find rp = 0.84184(67) fm, which differs by 5.0 standard deviations from the CODATA value of 0.8768(69) fm. Our result implies that either the Rydberg constant has to be shifted by −110 kHz/c (4.9 standard deviations), or the calculations of the QED effects in atomic hydrogen or muonic hydrogen atoms are insufficient.
Malnutrition is one of the world's most serious but least- addressed development challenge. Its human and economic costs are enormous, falling hardest on the poor, women and children. The present ...study was conducted at Nutritional rehabilitation center to know about the response of NRCs against malnutrition. The objective of study was to assess the factors responsible for the malnutrition. Sample of study were based on In-door patient ofNRCs on monthly basis. UNICEF standards were used in study for assessment of malnutrition. SD(>-2SD), MUAC (11.5cm), WFH (from given chart by UNICEF). In the study 77.77% population belongs to BPL category. 6 to 2 years children and girls are more affected by malnutrition. The present study revealed that NRC plays an important role but lack of awareness of population and illiteracy are barrier in nutrition improvement. So, Improvement of awareness level, Nutritional counseling and sanitation and women Improvement motivation is also important for the development of nutritional status of children. And Nutrition rehabilitation Center play an important role to improve child health as well as mother health.
This paper presents a comparison between Sensor or Indirect Field Oriented Control (IFOC) and Sensor-less Field Oriented Control (SFOC) in low frequency region for Induction Motor (IM). These two ...strategies can be considered among the family of Vector Control (VC) methods and provide a solution for high-performance drives. Most of the Electrically-operated Overhead Travelling (EOT) Crane IMs are controlled with vector control techniques. IM performance will deteriorate as frequency falls below 5 Hz due to its stator resistance drop. There are some critical requirements which needs rocket segments and satellite needs to be positioned in very precise position. For this EOT crane has to run in creep speed which needs drive has to run below 5 Hz. In this paper, the analysis is carried out on IFOC and SFOC methods and implemented to IM drives. In IFOC, flux magnitude and angle is achieved by imposing a slip frequency derived from the rotor dynamic equations with monitored rotor speed using external sensor such as encoder. Whereas SFOC does not require any sensor for estimation of flux magnitude and position, with monitored stator voltages and stator currents, flux magnitude and position can be achieved. Advantages and disadvantages of two control methods are emphasized in low frequency region (0-5 Hz). The theoretical results are found to be consistent with experimental results performed on 100 HP, three phase IM. It is concluded that IFOC method is better than SFOC method in low frequency region.
Future Collider Physics Detectors are envisioned with large granularity but we have a power delivery problem unless we fill a large fraction of the detector volume with copper conductors. LHC ...detector electronics is powered by transporting direct current over distances of 30 to 150 meters. This is how Thomas Alva Edison powered his light bulb. For example, CMS ECAL uses 50 kiloamps at 2.5 volts, supplied over a cable set with a transmission efficiency of only 30%. The transmission loss becomes waste heat in the detector that has to be removed. We have been exploring methods to transmit the DC power at higher voltage (low current), reducing to the final low voltage (high current) using DC-DC converters. These converters must operate in high magnetic fields and high radiation levels. This requires rad hard components and non-magnetic (air core) inductors.
Caloric Delineation of Gasoline Blends using Dsc Bharath, Evvala Satya; Subramanyam, Kothagundu
International journal of innovative technology and exploring engineering,
02/2020, Letnik:
4, Številka:
9
Journal Article
Odprti dostop
Petroleum by-products are now contemporary utilization rate it will be consuming in upcoming periods. Ethanol usage is one of the transport sectors can fulfill the requirement and contribute to ...mitigating the greenhouse gas emissions of the vehicles. In order to expand the SI engine which can function on 100% ethanol or append ethanol in petrol and operate the blends of that. The intention of this project is going to prepare the thermal and rheological behavior of pure petrol, E5 and E10, E15 ethanol-gasoline blend. All thermograms of heat flow exhibited at a 35ºC-280ºC temperature range at air atmosphere. This contemplation concludes that ethanol blending is the lowest exhaust gasses with considerable improvement in the performance of the Spark Ignition (SI) engine and promising, Ethanol as a new fuel which can be fortunately replace petrol and its depletion problem
Most new PCs have a new bus called PCI Express. It is a very high speed dual-simplex, point to point serial differential low voltage interconnect. The signaling rate is 2.5 Gbit per second, with 8/10 ...bit encoding to embed the clock in the data stream. On the transmit side parallel data is shifted out serially and on the receive side serial data is shifted into registers for parallel data output. The receiver also recovers the embedded clock. This new bus can be used to connect modules or boxes via twisted pair copper and is the bus of choice for high speed applications in the industrial world
The proton radius puzzle Antognini, A; Amaro, F D; Biraben, F ...
Journal of Physics: Conference Series,
09/2011, Letnik:
312, Številka:
3
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
By means of pulsed laser spectroscopy applied to muonic hydrogen (μ− p) we have measured the 2SF 11/2 – 2PF 23/2 transition frequency to be 49881.88(76) GHz 1. By comparing this measurement with its ...theoretical prediction 2, 3, 4, 5, 6, 7 based on bound-state QED we have determined a proton radius value of rp 0.84184(67) fm. This new value differs by 5.0 standard deviations from the COD ATA value of 0.8768(69) fm 8, and 3 standard deviation from the e-p scattering results of 0.897(18) fm 9. The observed discrepancy may arise from a computational mistake of the energy levels in μp or H, or a fundamental problem in bound-state QED, an unknown effect related to the proton or the muon, or an experimental error.
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