https://doi.org/10.1140/epjb/e2005-00208-2
Interpretation of experimental data near λ-transition point in liquid helium
Institute of Mathematics and Computer Science, University of Latvia,
29 Rainja Boulevard, LV-1459 Riga, Latvia
Corresponding author: a kaupuzs@com.latnet.lv
Received:
21
October
2004
Revised:
18
April
2005
Published online:
13
July
2005
The recently published experimental data for specific heat Cp
of liquid helium in zero gravity conditions very close to the
λ–transition have been discussed. We have shown
that these data allow different interpretations.
They can be well interpreted within the perturbative
RG approach and within our recently developed theory, as well.
Allowing the logarithmic correction, the corresponding fits lie
almost on top of each other over the whole range of the reduced
temperatures t (for bin averaged data)
.
However, the plot of the effective exponent 
suggests that the behaviour of Cp, probably, changes very close to 
.
To clarify this question, we need more accurate data for 
.
In addition, we show that the experimental data
for superfluid fraction of liquid helium close to
within ![$t \in [3 \times 10^{-7};10^{-4}]$](/articles/epjb/abs/2005/12/b04590/b04590_tex_eq7.png)
can be better fit
by our exponents 
, 
than by the RG exponents 
and 
.
The latter ones are preferable to fit the whole measured range
![$t \in [3 \times 10^{-7};10^{-2}]$](/articles/epjb/abs/2005/12/b04590/b04590_tex_eq12.png)
where, however, remarkable
systematic deviations appear.
Our estimated value 
of the asymptotic exponent ν
well agrees with the theoretical prediction 
.
PACS: 05.70.Jk – Critical point phenomena / 67.40.Kh – Thermodynamic properties / 65.20.+w – Thermal properties of liquids: heat capacity, thermal expansion, etc.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005
