• Aucun résultat trouvé

Table4.4byusingquadrupleprecision APPENDIX B

N/A
N/A
Protected

Academic year: 2021

Partager "Table4.4byusingquadrupleprecision APPENDIX B"

Copied!
22
0
0

Texte intégral

(1)

APPENDIX

B

Table 4.4 by using quadruple precision

Caption of Table 4.4: Absolute errors of the first ten ERPs for the n-p system. The absolute error is written in normalized scientific notation as ε = εsig× 10b, where εsig

is the significand and b is the order of magnitude. Here we report b only. Values in parenthesis from Ref. [49]. Units are shown in Table 3.1.

Table B.1: Table 4.4 by using quadruple precision.

(2)

112

Table B.2: Table 4.4 by using quadruple precision. Continuation of Table B.1.

a (fm) 15 17 19 N 20 30 40 20 30 40 20 30 40 b(a0) (−4)−4 (−7)−7 −7 −3 −7 −9 −4 −7 −11 b(r0) (−6)−6 (−8)−8 −8 −5 −9 −9 −5 −8 −10 b(P0) (−7)−7 (−8)−7 −7 −7 −9 −9 −7 −10 −10 b(Q0,3) −5 −5 −5 −6 −6 −6 −6 −7 −7 b(Q0,4) −4 −4 −4 −5 −5 −5 −6 −6 −6 b(Q0,5) −3 −3 −3 −4 −4 −4 −4 −4 −4 b(Q0,6) −2 −2 −2 −3 −3 −3 −4 −4 −4 b(Q0,7) −1 −1 −1 −2 −2 −2 −3 −3 −3 b(Q0,8) −1 −1 −1 −1 −1 −1 −2 −2 −2 b(Q0,9) −1 −1 −1 −1 −1 −1 −1 −1 −1

Comparing Tables 4.4 and B.2 one sees how high order parameters become more accurate when the precision is increased from double to quadruple.

Note how the loss of precision for a = 19 fm in Table 4.4 is corrected by increasing the numerical precision as Table B.2 displays.

Around a = 10 fm, the “strange” behavior of b(Q0,8) in Table B.1 has drawn our

attention. We think that this effect comes from the numerical rounding. For a future research, results of Q0,8 for channel radii around 10 fm are shown in Table B.3

Table B.3: b(Q0,8) in Table B.1 by choosing channel radii around 10 fm.

a (fm) 9.4, 9.5 or 9.6 9.7, 9.8 or 9.9 10.1, 10.2 or 10.3

N 20 30 40 20 30 40 20 30 40

(3)

APPENDIX

C

Error propagation

In science, theory and experiment have different and complementary perspectives. Some-times theories guide one to propose new experimental techniques to corroborate predic-tions, estimapredic-tions, behaviors, etc; sometimes experiments provide results which indicate us whether the theory gives an acceptable description of the phenomena under con-sideration or not. This is one of several ways to understand the role of theories and experiments in science. The important fact to stress is that theory and experiment have a very especial point of meeting. In this thesis that point is the phase shift or more precisely a function depending on the phase shift (the effective-range function).

Experimental phase shifts, δexpl,i = δexpl (Ei), are those extracted from the

partial-wave decomposition of the scattering amplitude which is determined from the measured differential cross sections for a given energy Ei. This implies that the experimental

uncertainty of the differential cross section is propagated up to δl,iexp (δl,iexp± σexpl,i with

σl,iexp the phase-shift error).

From the theoretical perspective rather than phase-shift points, a function δtheo

l (E;{β})

is provided (via the ERF in this thesis), where the parameter set {β} = { ¯β} satisfy δl,itheo ≈ δexpl,i . Thus, the challenge is to find a family of sets around { ¯β} capable of describing the experimental data according to the uncertainties.

The way to face this challenge can be very controversial, and therefore, a special review about it is provided here.

C.1

Statistical uncertainties or statistical errors

Let us assume x as continuous variable that can be associated with a physical quantity. As the name indicates, the statistical uncertainty σ of x provides a valuable piece of information about the confidence level of the x-value in a statistical context. Thus, σ defines an interval around x = ¯x where x is expected to be measured or determined with a high enough confidence level, with ¯x the most probable value.

At this point, one is induced wrongly to think that ¯x is the correct value of x, which is a deterministic point of view. Here we should understand x in a probabilistic frame,

(4)

C.2. χ2 method 114 and only when σ→ 0, the deterministic perspective makes sense. Thus in a formal way, x has a distribution of probability with a maximum in ¯x as Fig. C.1 illustrates.

¯ x 2σ

Figure C.1: Example of a x-distribution.

In physics, σ represents the error of x and is quantified by the standard deviation for symmetrical x-distributions. Thus, the convention x = ¯x± σ means that the interval [¯x− σ; ¯x + σ] is the most probable to find the true value of x (for a normal distribution this interval defines the 68.2% of probability).

For the moment, let me suppose that x represents δl,iexp and that we can determinate it experimentally. If we perform in the laboratory a first experiment, we can record our estimation as δl,iexp-1. Suppose now that we repeat the experiment and record our second estimation as δl,iexp-2. Clearly, there is no reason to think that both values are identical. We can keep repeating the experiment and recording our estimations. At the end, we shall see that our records show a range where δexpl,i usually falls, and then, we report δexpl,i = ¯δexpl,i ± σexpl,i which gives us an idea about the distribution in Fig. C.1.

This idea can be extended to an arbitrary energy set. The question is then, how can we describe consistently all the data set{¯δexpl,1 ± σl,1exp, ¯δl,2exp± σexpl,2 ,· · · , ¯δl,Nexp± σexpl,N}? This is the main goal of error propagation. Here we shall explore two proposals of error propagation: the χ2 method and the Monte Carlo technique.

C.2

χ

2

method

This is the most usual method to propagate errors (see for instance Ref. [75]). The assumptions of the method make it powerful in practice and limited in theory, which means that its application should be carried out carefully.

For a quantity y(x) [for example δl(E)] with an uncertainty σ, the assumptions are:

1. A set of N points ¯yi = ¯y(xi) together with their uncertainties σi are known.

2. Every point is normally distributed with mean ¯yi and standard deviation σi.

3. The errors are independent.

Under these assumptions the χ2 method finds a function f (x;{β}) (with {β} a set of free parameters) which maximizes the probability of finding{fi = f (xi;{β})} around

{¯yi}. This leads to minimize

χ2= N � n=1 (yi− fi)2 σ2 i (C.1) with respect to{β}.

(5)

C.3. Monte Carlo technique 115 function is expanded around { ¯β} which allows us to obtain the covariance matrix and the correlation matrix [75]. The latter has a form

     1 c1,2 . . . c1,Nβ c2,1 1 . . . c2,Nβ .. . ... . .. ... cNβ,1 cNβ,2 . . . 1      , (C.2)

with−1 < ci,j= cj,i< 1. If ci,j ≈ −1 (1), one says that βi and βj have a linear negative

(positive) relationship. If ci,j ≈ 0 there is no a linear relationship between them.

χ2-analyses for the potential model of the d-wave of12C+α (see Chapter 5) provide correlation matrices like

p2,1 q2,0 q2,1 q2,2 q2,3 p2,1 q2,0 q2,1 q2,2 q2,3       1 0.82 0.79 −0.77 0.69 0.82 1 0.30 −0.28 0.19 0.79 0.30 1 −0.99 0.98 −0.77 −0.28 −0.99 1 −0.99 0.69 0.19 0.98 −0.99 1      

In this example, the function to fit is a [1/3]-Pad´e approximant. Note that the non-diagonal elements are not close to zero in the sense |ci,j| << 1, and the function

is nonlinear on the parameters, which means that the standard χ2-method is not appropriate to propagate errors.

Box C.1: Example of a correlation matrix for fits in Chapter 5.

The correlation matrix provides a valuable information to apply error propagation by using the covariance matrix. If the model is linear on{β}, then χ2expansion up to second

order is exact and the errors are propagated correctly. If the model is approximately linear (or if ci,j ≈ 0 and |σi/yi| < 0.1, rule of thumb), the propagation can be accepted

as a valid approximation. Otherwise, the covariance matrix is not enough to provide a consistent error propagation and the relevant information is given by the correlation matrix and the diagonal elements of the covariance matrix.

C.3

Monte Carlo technique

Monte Carlo (MC) methods have a wide application in different fields. Here we shall see how this method is used to propagate uncertaintes [56, 76], or more precisely, distribu-tions.

As we have mentioned at the beginning of this appendix, by repeating an experiment we can determine the distribution of probability, and therefore, the uncertainty, of a given quantity x. This distribution provides all the information required to obtain the distribution of a function f (x) (note that we are in the field of functions of random variables). Let me illustrate this with an example. Suppose the typical case in physics where a variable x follows a normal distribution with standard deviation σx(x = ¯x±σx).

(6)

C.3. Monte Carlo technique 116 Fig. C.2 shows, the f -distribution is also a normal distribution with standard deviation σf = aσx. Note that the uncertainty of f is exactly the result obtained by the standard

error propagation. ¯ x 2σx ¯ f f (x) = ax σf = aσx 2σ f

Figure C.2: Schematic representation of error propagation via distributions. The example in Fig. C.2 is a simple one that can be proved formally. In general the function f (x) is more complicated than a straight line, and the f -distribution can be very difficult of finding theoretically. For these cases, the MC technique provides an accurate statistical method to overcome the difficulties of a formal deduction.

The idea behind MC is the same of repeating an experiment to determine the value and uncertainty of a quantity x. Specifically, MC generates x-values according with the experimental expectations, i.e., MC makes a set of x-values experimentally equiva-lent. Thus, if we know (or at least, if we can suppose or infer) the x-distribution, we can simulate the experiment via MC an arbitrary number of times. This allows us to propagate the x-distribution through an arbitrary function f (x) and therefore the error propagation can be carried out accurately. The only price to pay is that the set of x-values generated by MC should be large enough (usually several thousands) to rebuild the x-distribution. As an example, Fig. C.3 shows how MC recovers the distributions in Fig. C.2 by choosing a = 0.5 and x = 10± 1.

In this case, it is evident that the three: the formal deduction, the standard error propagation and the MC technique, provide the same result for σf. Unfortunately, this

is not valid in general and restricts the standard error propagation considerably as Fig. C.4 shows.

Note how MC provides a consistent f -distribution for all cases, and the standard error propagation only achieves that when the function is linear (or approximately linear around x = ¯x± σx). The reason is simple, the fact that x is normally distributed does

not mean that f (x) follows a normal distribution.

Up to now, we have explored the case of a function of a single random variable. This can be generalized for a multivariable function, for instance, χ2 or fi in Eq. (C.1), where

(7)

C.3. Monte Carlo technique 117 100 1000 10 000 100 000 x 4 6 8 10 12 14 16 4 6 8 10 12 14 16 4 6 8 10 12 14 16 4 6 8 10 12 14 16 f 2 3 4 5 6 7 8 2 3 4 5 6 7 8 2 3 4 5 6 7 8 2 3 4 5 6 7 8

Figure C.3: Example of distribution and error propagation by using MC technique. x = 10± 1 normally distributed and f(x) = 0.5x. Formal or exact distribution (dashed lines), MC technique (histograms) and σf-estimation by the standard error propagation

(solid lines = 2σf). The first row indicates the number of equivalent data sets generated

(8)

C.3. Monte Carlo technique 118 Σx 0.5 1 1.5 2 x 4 6 8 10 12 14 16 4 6 8 10 12 14 16 4 6 8 10 12 14 16 4 6 8 10 12 14 16 f1�x� 10 15 20 25 10 15 20 25 10 15 20 25 10 15 20 25 f2�x� 0.00 0.05 0.10 0.15 0.20 0.00 0.05 0.10 0.15 0.20 0.00 0.05 0.10 0.15 0.20 0.00 0.05 0.10 0.15 0.20 f3�x� 0.5 1.0 1.5 2.0 0.5 1.0 1.5 2.0 0.5 1.0 1.5 2.0 0.5 1.0 1.5 2.0

Figure C.4: f -distributions for x = 10± σx normally distributed and f1(x) = 1.5x + 3,

f2(x) = 10x−2 and f3(x) = tan(x/12). Exact (dashed lines), MC technique for 104 sets

(9)

APPENDIX

D

Fits and extrapolations

In this appendix we shall see how sensitive is an extrapolation according to the fit under several conditions. This will provide clear arguments to trust or not in a given estimation obtained from an extrapolation after a fit.

To start, Fig. D.1 shows a set of point according to a smooth function f (x)1. The

open circle will be the extrapolation point and our goal is to determinate it by using fits according to different sets of filled circles.

� � x0 a b c d f0 x0 a b c d f0

Figure D.1: Behavior (line) and set of data points (filled circles) for a given function f (x). a, b, c and d define the x-ranges in Fig. D.2.

In practice, one can understand the filled circles as data points coming from the ex-periment, which of course include uncertainties. Therefore we can analyze two scenarios for experimental data: with and without high precision as Fig. D.2 shows.

By analyzing Fig. D.2 from top to bottom, it is clear that2: First, with a few points at “small” x-values (close to a) the fit cannot describe correctly the curvature and therefore the extrapolation is compromised. Second, with the full input data set the fit provides a

1Note that this is general, i.e., f (x) represents an arbitrary quantity such as phase shift, distance,

temperature, etc.

2Here we wish to discuss the effect of an extrapolation in general terms. At the end of this appendix

(10)

120 global good description without any preference for “small” x-values, leading therefore to inaccurate extrapolations. Third, increasing arbitrarily the number of free parameters for finding a better extrapolation can provide the contrary effect and include unexpected behaviors for the extrapolation. Moreover, when there is not high precision, the extra flexibility introduced by more free parameters will try to explain the statistical fluctua-tions leading to inconsistent descripfluctua-tions and extrapolafluctua-tions. Fourth, the balance among all the previous effects (not too small/large x-range, not overestimate the flexibility for the fit) leads us to a consistent extrapolation.

� � x0 a b f0 x0 a b f0 �� x0 a b f0 x0 a b f0 � � x0 a d f0 x0 a d f0 �� x0 a d f0 x0 a d f0 � � x0 a d f0 x0 a d f0 �� x0 a d f0 x0 a d f0 � � x0 a c f0 x0 a c f0 �� x0 a c f0 x0 a c f0

(11)

121

The function f (x) is assumed as a polynomial of order 10 to provide a smooth (but not too simple) variation. Its coefficients are (from order 0 to 10): -1.000, 0.0833, -0.6319, 0.0700, -0.1375, 0.0261, -0.0308, 0.0080, -0.0071, 0.0023 and -0.0017.

The randomized data are generated by adding a random number between −0.1 and 0.1. The set of points used are listed below.

From top to bottom, the fits in Fig. D.2 correspond to polynomials of first, fourth, twelve and third order respectively.

x f (x) frand(x) 0.50 -1.12 -1.15 0.55 -1.15 -1.07 0.60 -1.18 -1.26 0.65 -1.22 -1.20 0.70 -1.26 -1.24 0.75 -1.31 -1.23 0.80 -1.36 -1.30 0.85 -1.41 -1.33 0.90 -1.48 -1.43 0.95 -1.54 -1.51 1.00 -1.62 -1.67 1.05 -1.70 -1.60 1.10 -1.79 -1.74 1.15 -1.89 -1.80 1.20 -2.00 -2.07 1.25 -2.12 -2.03 1.30 -2.25 -2.33 1.35 -2.40 -2.38 1.40 -2.56 -2.63 1.45 -2.75 -2.70 1.50 -2.95 -2.99 1.55 -3.18 -3.24 1.60 -3.44 -3.48 1.65 -3.74 -3.64 1.70 -4.08 -3.99 1.75 -4.48 -4.57 1.80 -4.95 -4.91 1.85 -5.50 -5.50 1.90 -6.16 -6.09

(12)
(13)

APPENDIX

E

Phase shift data from Ref. [1] for l = 2

Files README.TXT and table2.dat of Ref. [1] are shown in Boxes E.1 and, E.2, E.3 and E.4 respectively.

ARTICLE INFORMATION

Document Number: E-PRVCAN-79-032904 Journal: Phys. Rev. C 79, 055803 (2009)

All Authors: P. Tischhauser, A. Couture, R. Detwiler, J. Gorres, C. Ugarde, E.Stech, M. Wiescher, M. Heil, F. Kappeler, R. E. Azuma, L. Buchmann.

Title: Measurement of elastic12C+α scattering: Details of the experiment, analysis, and discussion of phase

shifts.

DEPOSIT INFORMATION

Description: The submitted files contain the phase shift information of the12C+α elastic scattering experiment

by P. Tischhauser et al. There are seven files according to the angular momenta l = 0 . . . 6. In each of these files the first column is the alpha energy, the second column the phase shift as derived from the globalized Monte Carlo simulations, the third column is the same phase shift randomized by the error from the Monte Carlo simulations and the fourth column is the error of the phase shifts from the Monte Carlo simulations. The files included are:

table0.dat - l = 0 phase shift information; table1.dat - l = 1 phase shift information; table2.dat - l = 2 phase shift information; table3.dat - l = 3 phase shift information; table4.dat - l = 4 phase shift information; table5.dat - l = 5 phase shift information; table6.dat - l = 6 phase shift information. Total No. of Files: 8

Filenames: README.TXT, table0.dat, table1.dat, table2.dat, table3.dat, table4.dat, table5.dat, table6.dat Filetypes: ASCII and .dat

Contact Information: Dr. Lothar R. Buchmann

TRIUMF - 4004 Wesbrook Mall - Vancouver, B.C. - CANADA V6T 2A3 Phone: 1+604-222-7403 / Fax: 1+604-222-1074 / Email: lothar@triumf.ca

Box E.1: File README.TXT of Ref. [1].

(14)

124

Line Eα(MeV) δ2 (◦) δ2rand(◦) σ2 (◦)

1 2.607 -0.353 -0.327 0.099 2.657 -0.389 -0.397 0.109 2.707 -0.427 -0.359 0.119 2.755 -0.464 -0.526 0.130 ! 2.808 -0.508 -0.448 0.142 ! 2.808 -0.508 -0.353 0.142 2.858 -0.551 -0.550 0.154 ! 2.903 -0.591 -0.409 0.165 ! 2.903 -0.591 -0.600 0.165 10 2.907 -0.594 -0.466 0.166 2.958 -0.641 -0.644 0.179 3.007 -0.687 -0.814 0.192 3.009 -0.689 -0.589 0.192 ! 3.049 -0.727 -0.689 0.203 ! 3.049 -0.727 -0.757 0.203 ! 3.049 -0.727 -0.801 0.203 3.098 -0.774 -0.780 0.217 3.110 -0.785 -0.762 0.220 3.134 -0.808 -0.909 0.227 20 3.200 -0.871 -0.764 0.246 3.202 -0.873 -0.999 0.247 3.203 -0.874 -1.043 0.247 3.205 -0.876 -0.926 0.247 3.248 -0.916 -1.217 0.260 3.307 -0.966 -1.117 0.278 ! 3.309 -0.967 -0.993 0.278 ! 3.309 -0.967 -1.087 0.278 3.346 -0.994 -1.294 0.290 3.396 -1.020 -0.657 0.305 30 3.398 -1.021 -0.889 0.306 3.411 -1.024 -1.420 0.310 3.435 -1.024 -1.098 0.318 ! 3.472 -0.997 -1.319 0.330 ! 3.472 -0.997 -0.775 0.330 3.510 -0.888 -1.192 0.343 ! 3.536 -0.649 -0.773 0.354 ! 3.536 -0.649 -0.760 0.354 3.547 -0.409 -0.133 0.360 3.548 -0.378 -0.139 0.361 40 3.558 0.119 -0.149 0.368 3.561 0.388 0.417 0.371 3.563 0.631 0.135 0.373 3.566 1.156 0.969 0.377 ! 3.568 1.691 1.575 0.380 ! 3.568 1.691 1.741 0.380 3.571 3.119 2.962 0.386 3.573 5.136 5.433 0.390 3.576 18.058 17.864 0.401 ! 3.578 136.425 136.394 0.411 50 ! 3.578 136.425 136.496 0.411 ! 3.578 136.425 136.239 0.411 3.581 170.468 170.076 2.424 3.583 173.367 173.321 0.887 3.586 -4.812 -4.517 4.049 ! 3.588 -4.172 -5.204 2.698 ! 3.588 -4.172 -7.721 2.698 3.591 -3.567 -4.068 0.823 ! 3.593 -3.294 -2.983 1.547 ! 3.593 -3.294 -1.220 1.547 60 3.596 -2.995 -2.956 0.338

Line Eα (MeV) δ2 (◦) δrand2 (◦) σ2(◦)

61 ! 3.598 -2.845 -2.904 0.316 ! 3.598 -2.845 -2.898 0.316 3.603 -2.574 -2.695 0.334 3.608 -2.394 -2.121 0.343 3.628 -2.041 -1.942 0.361 3.647 -1.907 -2.032 0.370 3.648 -1.903 -1.999 0.371 3.697 -1.793 -1.611 0.388 3.711 -1.785 -1.520 0.393 70 3.746 -1.782 -2.057 0.404 3.748 -1.782 -1.920 0.405 ! 3.796 -1.802 -2.218 0.419 ! 3.796 -1.802 -2.009 0.419 3.811 -1.811 -1.536 0.423 3.847 -1.836 -2.028 0.433 3.861 -1.847 -2.361 0.437 3.897 -1.876 -1.487 0.447 3.911 -1.888 -1.911 0.451 3.948 -1.920 -2.131 0.461 80 3.958 -1.928 -1.836 0.463 ! 4.012 -1.976 -2.057 0.477 ! 4.012 -1.976 -2.038 0.477 ! 4.012 -1.976 -2.327 0.477 ! 4.045 -2.004 -1.783 0.485 ! 4.045 -2.004 -1.744 0.485 ! 4.045 -2.004 -2.057 0.485 ! 4.059 -2.016 -2.341 0.515 ! 4.059 -2.016 -1.525 0.515 4.060 -2.017 -2.401 0.515 90 4.062 -2.019 -2.616 0.515 4.094 -2.046 -2.672 0.523 4.112 -2.061 -2.750 0.526 ! 4.148 -2.090 -1.993 0.534 ! 4.148 -2.090 -2.065 0.534 ! 4.162 -2.101 -1.596 0.537 ! 4.162 -2.101 -1.994 0.537 ! 4.175 -2.111 -1.776 0.540 ! 4.175 -2.111 -2.095 0.540 4.185 -2.118 -1.574 0.542 100 4.187 -2.120 -1.943 0.542 4.198 -2.128 -2.682 0.544 ! 4.212 -2.138 -2.264 0.547 ! 4.212 -2.138 -2.416 0.547 4.227 -2.148 -1.900 0.549 ! 4.228 -2.149 -2.291 0.550 ! 4.228 -2.149 -1.760 0.550 ! 4.228 -2.149 -2.476 0.550 4.237 -2.155 -2.934 0.551 ! 4.238 -2.156 -2.388 0.551 110 ! 4.238 -2.156 -2.112 0.551 4.248 -2.163 -1.969 0.553 ! 4.250 -2.164 -2.419 0.553 ! 4.250 -2.164 -2.274 0.553 4.258 -2.169 -1.542 0.555 4.262 -2.172 -2.075 0.556 4.263 -2.172 -1.988 0.556 4.268 -2.175 -2.585 0.557 ! 4.275 -2.180 -1.702 0.558 ! 4.275 -2.180 -1.693 0.558 120 ! 4.278 -2.182 -1.974 0.559

(15)

125

Line Eα (MeV) δ2 (◦) δrand2 (◦) σ2(◦)

121 ! 4.278 -2.182 -2.972 0.559 ! 4.288 -2.188 -2.896 0.560 ! 4.288 -2.188 -1.965 0.560 ! 4.288 -2.188 -2.480 0.560 4.297 -2.193 -2.558 0.561 ! 4.300 -2.195 -2.148 0.562 ! 4.300 -2.195 -2.156 0.562 4.312 -2.201 -2.660 0.563 4.313 -2.202 -1.663 0.564 130 4.323 -2.207 -2.385 0.565 4.328 -2.210 -2.442 0.566 4.332 -2.212 -2.094 0.566 4.338 -2.215 -2.640 0.567 4.342 -2.217 -1.899 0.568 4.347 -2.220 -2.081 0.568 4.353 -2.223 -1.879 0.569 4.359 -2.225 -2.393 0.570 ! 4.363 -2.227 -1.997 0.571 ! 4.363 -2.227 -2.749 0.571 140 ! 4.388 -2.238 -2.042 0.574 ! 4.388 -2.238 -2.382 0.574 ! 4.413 -2.247 -2.862 0.576 ! 4.413 -2.247 -2.372 0.576 4.419 -2.249 -1.612 0.577 4.447 -2.258 -2.138 0.580 ! 4.448 -2.258 -2.430 0.580 ! 4.448 -2.258 -2.336 0.580 4.463 -2.262 -2.394 0.581 4.464 -2.262 -2.745 0.581 150 4.512 -2.269 -2.432 0.585 ! 4.514 -2.270 -2.956 0.585 ! 4.514 -2.270 -2.554 0.585 4.549 -2.270 -2.893 0.586 4.565 -2.270 -2.438 0.587 4.615 -2.261 -2.186 0.587 4.649 -2.250 -2.852 0.586 4.650 -2.250 -1.394 0.586 4.665 -2.243 -2.212 0.585 4.715 -2.214 -1.488 0.570 160 4.737 -2.198 -2.084 0.072 4.765 -2.173 -1.763 0.602 4.816 -2.117 -2.358 0.587 4.851 -2.069 -2.103 0.582 4.865 -2.047 -1.665 0.579 4.915 -1.957 -2.025 0.571 4.948 -1.886 -1.798 0.564 4.962 -1.853 -1.930 0.561 5.016 -1.705 -1.692 0.522 ! 5.048 -1.601 -1.406 0.514 170 ! 5.048 -1.601 -1.453 0.514 5.066 -1.537 -1.557 0.509 ! 5.117 -1.326 -0.889 0.493 ! 5.117 -1.326 -1.541 0.493 5.141 -1.211 -1.231 0.485 5.167 -1.074 -0.819 0.475 5.171 -1.051 -0.680 0.474 5.189 -0.946 -0.523 0.466 5.207 -0.832 -0.458 0.459 ! 5.216 -0.772 -0.570 0.455 180 ! 5.216 -0.772 -1.180 0.455

Line Eα(MeV) δ2(◦) δ2rand(◦) σ2 (◦)

181 ! 5.216 -0.772 -0.794 0.455 5.224 -0.716 -0.310 0.452 5.228 -0.688 -0.600 0.450 5.232 -0.659 -0.966 0.449 5.235 -0.637 -0.764 0.447 5.237 -0.622 -0.507 0.446 5.238 -0.615 -0.829 0.446 ! 5.239 -0.607 -0.165 0.445 ! 5.239 -0.607 -0.598 0.445 190 5.240 -0.600 -0.435 0.445 5.241 -0.592 -0.580 0.444 5.242 -0.584 -0.687 0.444 5.243 -0.577 -0.448 0.444 5.244 -0.569 -1.120 0.443 5.245 -0.561 -0.677 0.443 5.246 -0.554 -0.240 0.442 ! 5.247 -0.546 -0.643 0.442 ! 5.247 -0.546 -0.779 0.442 5.249 -0.530 -0.497 0.441 200 5.250 -0.523 -0.516 0.440 ! 5.251 -0.515 0.006 0.440 ! 5.251 -0.515 -0.379 0.440 ! 5.254 -0.491 -0.049 0.439 ! 5.254 -0.491 -0.260 0.439 ! 5.254 -0.491 -0.560 0.439 ! 5.254 -0.491 -0.638 0.439 ! 5.256 -0.475 -1.108 0.438 ! 5.256 -0.475 -0.563 0.438 ! 5.259 -0.450 -0.413 0.436 210 ! 5.259 -0.450 -0.413 0.436 ! 5.259 -0.450 -0.424 0.436 ! 5.261 -0.434 -0.369 0.435 ! 5.261 -0.434 -0.374 0.435 5.263 -0.417 -0.402 0.434 5.274 -0.324 -0.137 0.429 ! 5.276 -0.306 0.265 0.428 ! 5.276 -0.306 -0.100 0.428 ! 5.276 -0.306 -0.303 0.428 ! 5.286 -0.216 -0.110 0.423 220 ! 5.286 -0.216 -0.623 0.423 5.297 -0.112 0.004 0.418 5.315 0.069 0.292 0.408 ! 5.316 0.080 0.000 0.408 ! 5.316 0.080 0.388 0.408 5.319 0.112 0.284 0.406 5.347 0.432 0.433 0.390 5.364 0.649 0.881 0.380 5.411 1.354 1.136 0.351 5.415 1.423 1.368 0.348 230 5.461 2.332 2.376 0.315 ! 5.518 3.880 3.951 0.267 ! 5.518 3.880 3.896 0.267 5.569 5.905 5.998 0.216 5.609 8.215 8.421 0.167 5.610 8.284 8.289 0.166 5.611 8.354 8.414 0.164 5.643 11.028 11.046 0.117 5.668 13.910 13.852 0.073 5.692 17.722 17.663 0.072 240 5.716 23.193 23.112 0.082

(16)

126

Line Eα(MeV) δ2 (◦) δrand2 (◦) σ2(◦)

241 5.719 24.043 23.911 0.083 5.743 32.812 32.907 0.111 5.763 44.011 43.908 0.160 5.768 47.582 47.429 0.168 ! 5.773 51.513 51.581 0.171 ! 5.773 51.513 51.404 0.171 5.784 61.472 61.365 0.161 5.794 71.963 70.808 2.002 5.799 77.578 77.625 0.642 250 5.804 83.316 83.183 0.263 ! 5.819 100.143 100.168 0.103 ! 5.819 100.143 100.171 0.103 ! 5.819 100.143 100.113 0.103 5.824 105.293 105.333 0.155 5.834 114.544 114.548 0.246 5.835 115.388 115.804 0.253 5.839 118.611 118.530 0.281 5.844 122.311 122.293 0.310 5.845 123.009 123.467 0.315 260 5.855 129.274 129.246 0.351 5.859 131.448 131.411 0.359 5.863 133.455 133.381 0.365 5.864 133.932 134.158 0.365 5.876 138.985 138.833 0.368 5.879 140.077 140.176 0.366 5.895 144.995 144.873 0.350 5.899 146.024 146.560 0.344 5.919 150.286 150.174 0.312 5.943 153.994 154.051 0.272 270 5.944 154.125 154.150 0.270 5.969 156.910 156.847 0.229 5.989 158.637 158.754 0.199 5.996 159.161 159.110 0.189 6.020 160.716 160.810 0.155 ! 6.041 161.829 161.944 0.127 ! 6.041 161.829 161.808 0.127 ! 6.041 161.829 161.792 0.127 ! 6.041 161.829 161.923 0.127 ! 6.042 161.877 161.856 0.125 280 ! 6.042 161.877 161.945 0.125 ! 6.042 161.877 161.901 0.125 ! 6.042 161.877 161.791 0.125 ! 6.042 161.877 161.844 0.125 ! 6.042 161.877 162.082 0.125 ! 6.042 161.877 161.783 0.125 ! 6.042 161.877 161.896 0.125 ! 6.042 161.877 161.960 0.125 ! 6.043 161.925 161.899 0.124 ! 6.043 161.925 161.899 0.124 290 ! 6.043 161.925 162.034 0.124 ! 6.043 161.925 161.938 0.124 ! 6.043 161.925 161.853 0.124 ! 6.043 161.925 161.801 0.124 ! 6.043 161.925 161.997 0.124 ! 6.043 161.925 161.842 0.124 ! 6.043 161.925 161.978 0.124 ! 6.043 161.925 162.150 0.124

Line Eα(MeV) δ2 (◦) δrand2 (◦) σ2(◦)

! 6.043 161.925 161.864 0.124 ! 6.043 161.925 161.752 0.124 300 ! 6.043 161.925 161.979 0.124 ! 6.043 161.925 161.900 0.124 ! 6.043 161.925 161.975 0.124 ! 6.043 161.925 161.758 0.124 ! 6.043 161.925 162.049 0.124 ! 6.043 161.925 161.851 0.124 ! 6.043 161.925 161.900 0.124 ! 6.043 161.925 161.965 0.124 ! 6.043 161.925 162.006 0.124 ! 6.043 161.925 161.925 0.124 310 ! 6.043 161.925 161.918 0.124 ! 6.043 161.925 162.029 0.124 ! 6.043 161.925 161.935 0.124 6.099 164.109 164.112 0.103 6.119 164.707 164.733 0.094 6.149 165.478 165.481 0.089 6.170 165.946 165.932 0.087 6.199 166.514 166.507 0.061 6.219 166.862 166.790 0.083 6.249 167.329 167.362 0.116 320 6.282 167.781 167.766 0.151 ! 6.298 167.980 168.097 0.168 ! 6.298 167.980 167.864 0.168 6.370 168.757 168.715 0.243 6.401 169.045 168.944 0.275 6.422 169.227 168.925 0.296 ! 6.474 169.644 169.801 0.348 ! 6.474 169.644 169.714 0.348 ! 6.485 169.727 169.606 0.359 ! 6.485 169.727 169.845 0.359 330 6.490 169.765 170.089 0.364 6.495 169.802 169.525 0.369 6.500 169.838 169.597 0.374 6.501 169.845 169.776 0.375 6.506 169.882 169.839 0.380 6.507 169.889 169.991 0.381 ! 6.511 169.918 170.085 0.385 ! 6.511 169.918 170.451 0.385 6.516 169.954 169.996 0.389 6.520 169.982 170.041 0.393 340 6.521 169.989 169.845 0.394 6.525 170.017 169.933 0.398 6.526 170.025 169.470 0.399 6.531 170.060 170.257 0.404 6.532 170.067 170.164 0.405 6.536 170.094 170.237 0.409 6.540 170.122 169.761 0.412 6.542 170.136 170.080 0.414 6.545 170.157 169.969 0.417 ! 6.571 170.333 170.979 0.442 350 ! 6.571 170.333 170.412 0.442 6.595 170.492 170.563 0.464 ! 6.620 170.655 171.328 0.487 ! 6.620 170.655 170.558 0.487 ! 6.620 170.655 170.628 0.487

(17)

Bibliography

[1] P. Tischhauser, A. Couture, R. Detwiler, J. G¨orres, C. Ugalde, E. Stech, M. Wi-escher, M. Heil, F. K¨appeler, R. E. Azuma, and L. Buchmann. EPAPS Document No. E-PRVCAN-79-032904 for Tables of 12C + α phase shifts., 2009.

[2] C. A. Bertulani and P. Danielewicz. Introduction to nuclear reactions. Graduate Student Series in Physics. Taylor & Francis, 2004.

[3] J. R. Taylor. Scattering theory: the quantum theory of nonrelativistic collisions. Dover Books on Engineering. Dover Publications, 2006.

[4] C. J. Joachain. Quantum collision theory. North-Holland, 1983.

[5] R. G. Newton. Scattering theory of waves and particles. Dover books on physics series. Dover Publications, 1982.

[6] I. J. Thompson and F. M. Nunes. Nuclear reactions for astrophysics: principles, calculation and applications of low-energy reactions. Cambridge University Press, 2009.

[7] P. Descouvemont and D. Baye. The R-matrix theory. Rep. Prog. Phys., 73:036301, 2010.

[8] C. Angulo and P. Descouvemont. R-matrix analysis of interference effects in

12C(α, α)12C and12C(α, γ)16O. Phys. Rev. C, 61:064611, 2000.

[9] J. Humblet. Elastic scattering and the K-matrix: (I). Expansion of the K-matrix . Nucl. Phys. A, 151:225, 1970.

[10] J. Humblet, P. Dyer, and B.A. Zimmerman. The K-matrix parametrization of the

12C + α cross section. Nucl. Phys. A, 271:210, 1976.

[11] R Huby. On Humblet’s modified K matrix. Journal of Physics G: Nuclear Physics, 5:295, 1979.

[12] J. Hamilton, I. Øverb¨o, and B. Tromborg. Coulomb corrections in non-relativistic scattering. Nucl. Phys. B, 60:443, 1973.

(18)

Bibliography 128 [13] Z. R. Iwinski, Leonard Rosenberg, and Larry Spruch. Radiative capture estimates via analytic continuation of elastic-scattering data, and the solar-neutrino problem. Phys. Rev. C, 29:349, 1984.

[14] C. R. Chen, G. L. Payne, J. L. Friar, and B. F. Gibson. Low-energy nucleon-deuteron scattering. Phys. Rev. C, 39:1261, 1989.

[15] H. A. Bethe. Energy production in stars. Phys. Rev., 55:434, 1939.

[16] D. D. Clayton. Principles of stellar evolution and nucleosynthesis. University of Chicago Press, 1968.

[17] E. G. Adelberger, A. Garc´ıa, R. G. Hamish Robertson, K. A. Snover, A. B. Bal-antekin, K. Heeger, M. J. Ramsey-Musolf, D. Bemmerer, A. Junghans, C. A. Bertu-lani, J.-W. Chen, H. Costantini, P. Prati, M. Couder, E. Uberseder, M. Wiescher, R. Cyburt, B. Davids, S. J. Freedman, M. Gai, D. Gazit, L. Gialanella, G. Imbri-ani, U. Greife, M. Hass, W. C. Haxton, T. Itahashi, K. Kubodera, K. Langanke, D. Leitner, M. Leitner, P. Vetter, L. Winslow, L. E. Marcucci, T. Motobayashi, A. Mukhamedzhanov, R. E. Tribble, Kenneth M. Nollett, F. M. Nunes, T.-S. Park, P. D. Parker, R. Schiavilla, E. C. Simpson, C. Spitaleri, F. Strieder, H.-P. Trautvet-ter, K. Suemmerer, and S. Typel. Solar fusion cross sections. II. The pp chain and CNO cycles. Rev. Mod. Phys., 83:195, 2011.

[18] C. A. Bertulani. Nuclear physics in a nutshell. In a Nutshell. Princeton University Press, 2007.

[19] S. Mohamed, J. Mackey, and N. Langer. 3D simulations of Betelgeuse’s bow shock. A&A, 541:A1, 2012.

[20] I. Strakovsky and L. Blokhintsev. The universe evolution: astrophysical and nuclear aspects. Physics research and technology. Nova Science Publishers, Incorporated, 2013.

[21] C. Iliadis. Nuclear physics of stars. Wiley, 2008.

[22] L. R. Buchmann and C. A. Barnes. Nuclear reactions in stellar helium burning and later hydrostatic burning stages. Nucl. Phys. A, 777:254, 2006. Special Issue on Nuclear Astrophysics.

[23] R. Kunz, M. Fey, M. Jaeger, A. Mayer, J. W. Hammer, G. Staudt, S. Harissopulos, and T. Paradellis. Astrophysical Reaction Rate of 12C(α, γ)16O. The Astrophysical Journal, 567:643, 2002.

[24] C. R. Brune, W. H. Geist, R. W. Kavanagh, and K. D. Veal. Sub-Coulomb α transfers on 12C and the 12C(α, γ)16O S factor. Phys. Rev. Lett., 83:4025–4028, 1999.

[25] L. Buchmann. Radiative cascade transitions and the12C(α, γ)16O E2 cross section

(19)

Bibliography 129 [26] P. Tischhauser, R. E. Azuma, L. Buchmann, R. Detwiler, U. Giesen, J. G¨orres, M. Heil, J. Hinnefeld, F. K¨appeler, J. J. Kolata, H. Schatz, A. Shotter, E. Stech, S. Vouzoukas, and M. Wiescher. Elastic α−12C Scattering and the12C(α, γ)16O E2

S factor. Phys. Rev. Lett., 88:072501, 2002.

[27] M. Dufour and P. Descouvemont. 12C(α, γ)16O E2 cross section: R-matrix fits combined with a microscopic cluster model. Phys. Rev. C, 78:015808, 2008.

[28] J-M. Sparenberg. Clarification of the relationship between bound and scattering states in quantum mechanics: Application to 12C+α. Phys. Rev. C, 69:034601,

2004.

[29] O. L. Ram´ırez Su´arez and J-M. Sparenberg. Precise determination of the effective-range parameters up to an arbitrary order. Phys. Rev. C, 88:014601, 2013.

[30] D. Baye and E. Brainis. Zero-energy determination of the astrophysical S factor and effective-range expansions. Phys. Rev. C, 61:025801, 2000.

[31] A. M. Mukhamedzhanov and R. E. Tribble. Connection between asymptotic nor-malization coefficients, subthreshold bound states, and resonances. Phys. Rev. C, 59:3418, 1999.

[32] R. Yarmukhamedov and D. Baye. Connection between effective-range expansion and nuclear vertex constant or asymptotic normalization coefficient. Phys. Rev. C, 84:024603, 2011.

[33] P. Tischhauser, A. Couture, R. Detwiler, J. G¨orres, C. Ugalde, E. Stech, M. Wi-escher, M. Heil, F. K¨appeler, R. E. Azuma, and L. Buchmann. Measurement of elastic 12C + α scattering: Details of the experiment, analysis, and discussion of

phase shifts. Phys. Rev. C, 79:055803, 2009.

[34] C. Cohen-Tannoudji, B. Diu, and F. Lalo¨e. Quantum mechanics I. Quantum Mechanics. Wiley, 1991.

[35] A. Galindo and P. Pascual. Quantum mechanics I. Texts and Monographs in Physics. Springer-Verlag, 1990.

[36] C. L. Pekeris. The Rotation-Vibration Coupling in Diatomic Molecules. Phys. Rev., 45:98, 1934.

[37] H. A. Bethe. The Meson Theory of Nuclear Forces I. General Theory. Phys. Rev., 57:260, 1940.

[38] A. Bohr and B. R. Mottelson. Nuclear structure I. Single Structure Motion. World Scientific, 1998.

[39] G. B. Arfken and H. J. Weber. Mathematical methods for physicists. Har-court/Academic Press, 2001.

(20)

Bibliography 130 [41] L. F. Canto and S. Hussein. Scattering theory of molecules, atoms and nuclei. World

Scientific, 2013.

[42] P. Swan. Asymptotic phase-shifts and bound states for two-body central interac-tions. Nucl. Phys., 46:669, 1963.

[43] A. C. Allison. The numerical solution of coupled differential equations arising from the Schr¨odinger equation. Journal of Computational Physics, 6:378, 1970.

[44] V. I. Kukulin, V. M. Krasnopolsky, and J. Hor´aˇcek. Theory of resonances: principles and applications. Reidel Texts in the Mathematical Sciences. Kluwer, 1989.

[45] L. D. Blokhintsev. On the determination of asymptotic normalization coefficients. Few-Body Systems, 44:195, 2008.

[46] J. M. Blatt and J. D. Jackson. On the Interpretation of Neutron-Proton Scattering Data by the Schwinger Variational Method. Phys. Rev., 76:18, 1949. [In the paper: Vol. 26, Online: Vol. 76].

[47] J. Schwinger. A variational principle for scattering problems. Phys. Rev., 72:742, 1947.

[48] A Deloff. Effective range function below threshold. Journal of Physics G: Nuclear and Particle Physics, 26:1817, 2000.

[49] D. Baye, M. Hesse, and R. Kamouni. Lagrange mesh calculation of the effective range expansion. Phys. Rev. C, 63:014605, 2000.

[50] J.M. Blatt and V.F. Weisskopf. Theoretical nuclear physics. John Wiley, 1958. [51] R. G. Newton and Thomas Fulton. Phenomenological Neutron-Proton Potentials.

Phys. Rev., 107:1103, 1957.

[52] T. F. O’Malley, Larry Spruch, and Leonard Rosenberg. Modification of Effective-Range Theory in the Presence of a Long-Effective-Range (r−4) Potential. Journal of Mathe-matical Physics, 2:491, 1961.

[53] M. Pav´on Valderrama and E. Ruiz Arriola. Low-energy NN scattering at next-to-next-to-next-to-next-to-leading order for partial waves with j ≤ 5. Phys. Rev. C, 72:044007, 2005.

[54] H. van Haeringen and L. P. Kok. Modified effective-range function. Phys. Rev. A, 26:1218, 1982.

[55] C. Bloch. Une formulation unifi´ee de la th´eorie des r´eactions nucl´eaires. Nucl. Phys., 4:503, 1957.

[56] W. H. Press. Numerical recipes in Fortran 77: the art of scientific computing. Vol 1. Cambridge University Press, 1992.

(21)

Bibliography 131 [58] J-M. Sparenberg, P. Capel, and D. Baye. Influence of low-energy scattering on

loosely bound states. Phys. Rev. C, 81:011601, 2010.

[59] J-M. Sparenberg, P. Capel, and D. Baye. Deducing physical properties of weakly bound states from low-energy scattering data. application to16o and12C + α. Jour-nal of Physics: Conference Series, 312:082040, 2011.

[60] G. Audi, A. H. Wapstra, and C. Thibault. The Ame2003 atomic mass evalua-tion: (II). Tables, graphs and references. Nucl. Phys. A, 729:337, 2003. The 2003 NUBASE and Atomic Mass Evaluations.

[61] Triangle Universities Nuclear Laboratory (TUNL).

Nu-clear data evaluation project, “energy level diagram, 16O”.

http://www.tunl.duke.edu/nucldata/figures/16figs/16 08 1993.pdf.

[62] R. Plaga, H. W. Becker, A. Redder, C. Rolfs, H. P. Trautvetter, and K. Langanke. The scattering of alpha particles from 12C and the 12C(α, γ)16O stellar reaction rate. Nucl. Phys. A, 465:291, 1987.

[63] P. Descouvemont. Internal comunication, 2014.

[64] Sucheta Adhikari and Chinmay Basu. The ANC of 16O subthreshold states from 12C(6Li, d) reaction at energies near the barrier. Phys. Lett. B, 704:308, 2011.

[65] Y. C. Tang, M. LeMere, and D. R. Thompsom. Resonating-group method for nuclear many-body problems. Phys. Rep., 47:167, 1978.

[66] Y. Suzuki, K. Yabana, R. G. Lovas, and K. Varga. Structure and reactions of light exotic nuclei. Taylor & Francis, 2003.

[67] James J. Griffin and John A. Wheeler. Collective Motions in Nuclei by the Method of Generator Coordinates. Phys. Rev., 108:311, 1957.

[68] H. Horiuchi. Chapter III. Kernels of GCM, RGM and OCM and their calculation methods. Prog. Theor. Phys. Suppl., 62:90, 1977.

[69] B. Buck, H. Friedrich, and C. Wheatley. Local potential models for the scattering of complex nuclei. Nucl. Phys. A, 275:246, 1977.

[70] P. Capel, G. Goldstein, and D. Baye. Time-dependent analysis of the breakup of

11Be on 12C at 67 MeV/nucleon. Phys. Rev. C, 70:064605, 2004.

[71] K. Wildermuth and Th. Kanellopoulos. The “cluster model” of the atomic nuclei. Nucl. Phys., 7:150, 1958.

[72] D. Baye and N. Pecher. Generator-coordinate description of heavy-ion collisions with a spin-orbit force. Acad. Roy. Belg. Bull. Cl. Sci., 5(LXVII):835, 1981. [73] H. H¨usken. Application of the generator coordinate method to the scattering of

deformed nuclei. Nucl. Phys. A, 291:206, 1977.

[74] D. Baye. Behavior of the7Be(p, γ)8B astrophysical S factor near zero energy. Phys.

(22)

Bibliography 132 [75] J. R. Taylor. An introduction to error analysis: the study of uncertainties in physical

measurements. Series of books in physics. University Science Books, 1982.

[76] J. Tellinghuisen. Statistical error propagation. J. Phys. Chem. A, 105:3917, 2001. [77] L. Kirkup. Data analysis with Excel�: an introduction for physical scientists.R

Cambridge University Press, 2002.

[78] L. Kirkup. Data analysis for physical scientists: featuring Excel�. CambridgeR

Références

Documents relatifs

Notre recherche montre que la stabilité des étangs de plus de 1,8 m de profondeur, quantifiée par le Nombre de Wedderburn, est plus durable qu’il n’est habituellement

Overall, the findings of the present study based on oxygen time series in the water column, DOU calculations, and DIC flux discrepancy between benthic exchange fluxes and

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des

We statistically evaluated the relative orientation between gas column density structures, inferred from Herschel submillimetre ob- servations, and the magnetic field projected on

the temperature is low ( Fig. The reason for this energy dependence is the non-linearity of Eqs. B2.2) The central area of the bottom solid-etchant interface of a partially

In the stratocumulus and coastal stratus regimes, SCMs without activated shallow convection generally simulated negative cloud feed- backs, while models with active shallow

Black diamonds – aircraft measurements; red crosses – TES retrievals on the days of the aircraft measurements; blue rectangles – GEOS-Chem results sampled along the TES orbital

Plus tard, elle lui confia qu'elle avait remarquée, bien avant qu'il se décidât à l'inviter, sa prestance et son port racé.. - Dis-moi que c'est pour la