اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدSearch for a new short-range spin-dependent force with polarized Helium 3
135
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
Measuring the depolarization rate of a $^3$He hyperpolarized gas is a sensitive method to probe hypothetical short-range spin-dependent forces. A dedicated experiment is being set up at the Institute Laue Langevin in Grenoble to improve the sensitivity. We presented the status of the experiment at the 10th PATRAS Workshop on Axions, WIMPs and WISPs.
قيم البحث
اقرأ أيضاً
We have searched for a short-range spin-dependent interaction mediated by a hypothetical light scalar boson with CP-violating couplings to the neutron using the spin relaxation of hyperpolarized $^3$He. The walls of the $^3$He cell would generate a depolarizing pseudomagnetic field.
We have searched for a short-range spin-dependent interaction using the spin relaxation of hyperpolarized $^3$He. Such a new interaction would be mediated by a hypothetical light scalar boson with CP-violating couplings to the neutron. The walls of t
he $^3$He cell would generate a pseudomagnetic field and induce an extra depolarization channel. We did not see any anomalous spin relaxation and we report the limit for interaction ranges $lambda$ between $1$ and $100~rm{mu m}$: $g_sg_p lambda ^2 leq 2.6times 10^{-28}~mathrm{m^2}, ( 95~%, mathrm{C.L.})$, where $g_s$($g_p$) are the (pseudo)scalar coupling constant, improving the previous best limit by 1 order of magnitude.
We propose a new method to detect short-range textit{P-} and textit{T-} violating interactions between nucleons, based on measuring the precession frequency shift of polarized $^3$He nuclei in the presence of an unpolarized mass. To maximize the sens
itivity, a high-pressure $^3$He cell with thin glass windows (250 $rmmu m$) is used to minimize the distance between the mass and $^3$He. The magnetic field fluctuation is suppressed by using the $^3$He gas in a different region of the cell as a magnetometer. Systematic uncertainties from the magnetic properties of the mass are suppressed by flipping both the magnetic field and spin directions. Without any magnetic shielding, our result has already reached the sensitivity of the current best limit. With improvement in uniformity and stability of the field, we can further improve the sensitivity by two orders of magnitude over the force range from $10^{-4}-10^{-2}$ m.
We investigate the sensitivities of searches for exotic spin-dependent interactions between the polarized nuclear spins of $^3$He and the particles of unpolarized or polarized solid-state masses using the frequency method and the resonance method. In
the frequency method, the spin-dependent interactions act as an effective static magnetic field, causing the frequency shift to the spin precession of $^{3}$He. In the resonance method, proposed by Arvanitaki and Geraci [Phys. Rev. Lett. 113, 161801 (2014)] for the significant improvement of the experimental sensitivities on the spin-dependent interactions, the mass movement is modulated at the Larmor frequency of $^3$He. This results in the modulating spin-dependent interactions inducing an effective oscillatory magnetic field, which can tilt the $^3$He spins, similarly as an oscillatory magnetic field in nuclear magnetic resonance. We estimate the sensitivities of the searches using a room-temperature $^3$He target for its extremely long relaxation time. New limits on the coupling strengths of the spin-dependent interactions can be set in the interaction length range below $10^{-1}$ m.
In our quest for investigating the nature of dark matter from the way its constituents interact with ordinary matter, we propose an experiment using a pbo ~calorimeter to search for or set new limits on the production rate of i) hidden sector dark ma
tter mediator in the $3 - 60$ MeV mass range via their $e^+e^-$ decay (or $gammagamma$ decay with limited tracking), and ii) the hypothetical X17 particle, claimed in two recent experiments. The search for these particles is motivated by new dark matter models and candidates introduced to account for the small-scale structure in astrophysical observations and anomalies such as the 4.2$sigma$ disagreement between experiments and the standard model prediction for the muon anomalous magnetic moment, and the excess of $e^+e^-$ pairs from the $^8$Be M1 nuclear transition to its ground state observed by the ATOMKI group. In these models the $1 - 100$ MeV mass range is particularly well-motivated and the lower part of this range still remains unexplored. The proposed direct detection experiment will use a magnetic-spectrometer-free setup (the PRad apparatus) to detect all three final state particles in the visible decay of the dark matter mediator allowing for an effective control of the background and will cover the mass range in a single setting. The use of the well-demonstrated PRad setup allows for an essentially ready-to-run and uniquely cost-effective search for dark matter mediator in the $3 - 60$ MeV mass range with a sensitivity of 7.2$times$10$^{-8}$ - 5.9$times$10$^{-9}$ to $epsilon^2$ the square of kinetic mixing interaction coupling constant. In the first appendix, we show an example of this type of analysis using the $^{12}$C data from the PRad experiment. In the second appendix, we detail the additional work that was done after submitting this proposal before presenting at the JLab PAC49.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
