arXiv subjects

H. Päs

Publications and source records attributed to H. Päs.

43 records · Page 3Linked to original sources

arXiv1998

New limits on dark--matter WIMPs from the Heidelberg--Moscow experiment

New results after 0.69 kg yr of measurement with an enriched 76Ge detector of the Heidelberg--Moscow experiment with an active mass of 2.758 kg are presented. An energy threshold of 9 keV and a background level of 0.042 counts/(kg d keV) in the energy region between 15 keV and 40 keV was reached.The derived limits on the WIMP--nucleon cross section are the most stringent limits on spin--independent interactions obtained to date by using essentially raw data without background subtraction.

hep-ex↗

arXiv1998

Test of Special Relativity and Equivalence Principle from Neutrinoless Double Beta Decay

We generalize the formalism for testing Lorentz invariance and the equivalence principle in the neutrino sector. While neutrino oscillation bounds constrain the region of large mixing of the the weak and gravitational eigenstates, we obtain new constraints on violations of Lorentz invariance and the equivalence principle from neutrinoless double beta decay. These bounds apply even in the case of no mixing and thus probe a totally unconstrained region in the parameter space.

hep-ph↗

arXiv1998

New physics potential of double beta decay and dark matter search

The search for neutrinoless double beta decay and WIMP dark matter has a broad potential to test particle physics beyond the standard model. During the last years, the analysis of various contributions to the double beta decay rate by the Heidelberg group led, besides the most restrictive limit on the effective Majorana neutrino mass, to bounds on left-right-symmetric models, leptoquarks and supersymmetry. In a general framework bounds on arbitrary lepton number violating theories can be derived. Using double beta technology for direct dark matter detection, stringent limits on the spin-independent WIMP--nucleon interaction have been obtained. These results deduced from the Heidelberg-Moscow double beta decay experiment are reviewed. Also an outlook on the future of double beta decay and dark matter search, the GENIUS proposal, is given.

hep-ph↗

arXiv1997

Search for New Physics with Neutrinoless Double Beta Decay

Neutrinoless double beta decay ($0νββ$) is one of the most sensitive approaches to test particle physics beyond the standard model. During the last years, besides the most restrictive limit on the effective Majorana neutrino mass, the analysis of new contributions by the Heidelberg group led to bounds on left-right-symmetric models, leptoquarks and R-parity violating models competitive to recent accelerator limits, which are of special interest in view of the HERA anomaly at large $Q^2$ and $x$. These new results deduced from the Heidelberg-Moscow double beta decay experiment are reviewed. Also an outlook on the future of double beta decay, the GENIUS proposal, is given.

hep-ph↗

arXiv1997

A general parametrization for the long-range part of neutrinoless double beta decay

Double beta decay has been proven to be a powerful tool to constrain $B-L$ violating physics beyond the standard model. We present a representation for the long-range part of the general $0νββ$ decay rate allowed by Lorentz-invariance. Combined with the short range part this general parametrization in terms of effective $B-L$ violating couplings will provide the $0νββ$ limits on arbitrary lepton number violating theories.

hep-ph↗

arXiv1997

A Xenon Solar Neutrino Detector

The neutrino capture by $^{131}$Xe with a threshold at 352 keV as reaction to detect solar neutrinos is examined. The most important feature of this process is its high sensitivity to beryllium neutrinos, which contribute approximately 40% to the total capture rate (45 SNU) assuming the fluxes predicted by the Standard Solar Model.

nucl-ex↗

arXiv1995

On the observability of Majoron emitting double beta decays

Because of the fine--tuning problem in classical Majoron models in recent years several new models were invented. It is pointed out that double beta decays with Majoron emission depend on new matrix elements, which have not been considered in the literature. A calculation of these matrix elements and phase space integrals is presented. We find that for new Majoron models extremely small decay rates are expected.

hep-ph↗