Do you want to publish a course? Click here

Transient thermal effects in solid noble gases as materials for the detection of Dark Matter

214   0   0.0 ( 0 )
 Added by Sorina Lazanu
 Publication date 2011
  fields Physics
and research's language is English




Ask ChatGPT about the research

The transient phenomena produced in solid noble gases by the stopping of the recoils resulting from the elastic scattering processes of WIMPs from the galactic halo were modelled, as dependencies of the temperatures of lattice and electronic subsystems on the distance to the recoils trajectory, and time from its passage. The peculiarities of these thermal transients produced in Ar, Kr and Xe were analysed for different initial temperatures and WIMP energies, and were correlated with the characteristics of the targets and with the energy loss of the recoils. The results were compared with the thermal spikes produced by the same WIMPs in Si and Ge. In the range of the energy of interest, up to tens of keV for the self-recoil, local phase transitions solid - liquid and even liquid - gas were found possible, and the threshold parameters were established.



rate research

Read More

181 - Laura Baudis 2014
Cosmological observations and the dynamics of the Milky Way provide ample evidence for an invisible and dominant mass component. This so-called dark matter could be made of new, colour and charge neutral particles, which were non-relativistic when they decoupled from ordinary matter in the early universe. Such weakly interacting massive particles (WIMPs) are predicted to have a non-zero coupling to baryons and could be detected via their collisions with atomic nuclei in ultra-low background, deep underground detectors. Among these, detectors based on liquefied noble gases have demonstrated tremendous discovery potential over the last decade. After briefly introducing the phenomenology of direct dark matter detection, I will review the main properties of liquefied argon and xenon as WIMP targets and discuss sources of background. I will then describe existing and planned argon and xenon detectors that employ the so-called single- and dual-phase detection techniques, addressing their complementarity and science reach.
Particles weakly interacting with ordinary matter, with an associated mass of the order of an atomic nucleus (WIMPs), are plausible candidates for Dark Matter. The direct detection of an elastic collision of a target nuclei induced by one of these WIMPs has to be discriminated from the signal produced by the neutrons, which leaves the same signal in a detector. The MIMAC (MIcro-tpc MAtrix of Chambers) collaboration has developed an original prototype detector which combines a large pixelated Micromegas coupled with a fast, self-triggering, electronics. Aspects of the two-chamber module in operation in the Modane Underground Laboratory are presented: calibration, characterization of the $^{222}$Rn progeny. A new test bench combining a MIMAC chamber with the COMIMAC portable quenching line has been set up to characterize the 3D tracks of low energy ions in the MIMAC gas mixture: the preliminary results thereof are presented. Future steps are briefly discussed.
The detection of gravitational waves from compact binary mergers by LIGO has opened the era of gravitational wave astronomy, revealing a previously hidden side of the cosmos. To maximize the reach of the existing LIGO observatory facilities, we have designed a new instrument that will have 5 times the range of Advanced LIGO, or greater than 100 times the event rate. Observations with this new instrument will make possible dramatic steps toward understanding the physics of the nearby universe, as well as observing the universe out to cosmological distances by the detection of binary black hole coalescences. This article presents the instrument design and a quantitative analysis of the anticipated noise floor.
92 - R. Bernabei 2009
A technical and methodological comparison of the liquid noble gas experiments is presented and the low energy physics application of double phase noble gas detectors in direct Dark Matter investigations is discussed.
The $Lambda$CDM prediction of $S_8equivsigma_8(Omega_m/0.3)^{0.5}$ -- where $sigma_8$ is the root mean square of matter fluctuations on a 8 $h^{-1}$Mpc scale -- once calibrated on Planck CMB data is $2-3sigma$ lower than its direct estimate by a number of weak lensing surveys. In this paper, we explore the possibility that the $S_8$-tension is due to a non-thermal hot dark matter (HDM) fractional contribution to the universe energy density leading to a power suppression at small-scales in the matter power spectrum. Any HDM models can be characterized by its effective mass $ m_{sp}^{rm eff}$ and its contribution to the relativistic degrees of freedom at CMB decoupling $Delta N_{rm eff}$. Taking the specific example of a sterile particle produced from the decay of the inflaton during a matter dominated era, we find that from Planck only the tension can be reduced below $2sigma$, but Planck does not favor a non-zero ${m_{sp}^{rm eff},Delta N_{rm eff}}$. In combination with a measurement of $S_8$ from KIDS1000+BOSS+2dfLenS, the $S_8$-tension would hint at the existence of a particle of mass $ m_{sp}^{rm eff} simeq 0.67_{-0.48}^{+0.26}$ ${rm eV}$ with a contribution to $Delta N_{rm eff} simeq0.06pm0.05$. However, Pantheon and BOSS BAO/$fsigma_8$ data restricts the particle mass to $m_{sp}^{rm eff} simeq 0.48_{-0.36}^{+0.17}$ and contribution to $Delta N_{rm eff} simeq 0.046_{-0.031}^{+0.004}$. We discuss implications of our results for other canonical non-thermal HDM models -- the Dodelson-Widrow model and a thermal sterile particle with a different temperature in the hidden sector. We report competitive results on such hidden sector temperature which might have interesting implications for particle physics model building, in particular connecting the $S_8$-tension to the longstanding short baseline oscillation anomaly.
comments
Fetching comments Fetching comments
Sign in to be able to follow your search criteria
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا